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Re: [ccd-newastro] Full Write-up on Embedding the ICC Color Profile into our Jpgs

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  • Paul Beskeen
    ... Hi Neil, Many Thanks for drawing people attention to this. A couple of questions: 1) I don t understand what benefit you would get if you continue to save
    Message 1 of 15 , Jul 1, 2008
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      Neil Fleming wrote:
      > A little O/T, but here is the compilation of the notes
      > from the last few days.
      >
      > This write-up illustrates how to set up full ICC color
      > profiling in Firefox 3 (so you can view the corrected
      > image that the author intended you to see), as well as
      > how to set up color profiling and embed the ICC color
      > profile into your own jpgs.
      >
      > http://www.flemingastrophotography.com/iccprofiling.html

      Hi Neil,

      Many Thanks for drawing people attention to this. A couple of questions:

      1) I don't understand what benefit you would get if you continue to save
      in sRGB colour space (as suggested by your workflow) but with "color
      profile" ticked. The default for all browsers is sRGB.

      2) If you save in an alternative colour space - such as Adobe RGB, then
      won't people without ICC enabled browsers see some very strange effects?

      Cheers, Paul.
      --
      http://www.beskeen.com
    • Neil Fleming
      ... Think of it this way. The sRGB color space represents the range of values that you *can* work with. Like the range of choices on a bingo card. Unless you
      Message 2 of 15 , Jul 1, 2008
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        --- Paul Beskeen <yahoo@...> wrote:
        > Hi Neil,
        >
        > 1) I don't understand what benefit you would get if
        > you continue to save
        > in sRGB colour space (as suggested by your workflow)
        > but with "color
        > profile" ticked. The default for all browsers is
        > sRGB.

        Think of it this way. The sRGB color space represents
        the range of values that you *can* work with. Like
        the range of choices on a bingo card.

        Unless you are viewing an image with the color profile
        embedded, *and* your program will accommodate that
        mapping, you will see "uncontrolled" results rather
        than that the author intended. "B5" on your bingo
        card could be "B7" on another's.

        Just take a look at the ICC example in the original
        e-mail. The authors picked (on purpose) an extreme
        example, but it illustrates the point well.

        > 2) If you save in an alternative colour space - such
        > as Adobe RGB, then
        > won't people without ICC enabled browsers see some
        > very strange effects?

        I wouldn't necessarily call it "extreme", but there
        would be minor differences. Adobe RGB is better
        adapted to printing, with its wider gamut than sRGB.
        Some of the colors would be shifted to something you
        can see. What you see on your monitor would not what
        would be printed, unless you have a high-end monitor
        like an Eizo, one that is capable of displaying the
        full Adobe 1998 gamut.

        ...Neil

        www.flemingastrophotography.com
        Direct from Boston - brilliant diamonds in pea soup
        Also check out the astro_narrowband Yahoo group!
      • Paul Beskeen
        Hi Neil, ... I don t mean to be argumentative here, and I m certainly no expert in colour management, but I guess it comes down to the question do ICC aware
        Message 3 of 15 , Jul 2, 2008
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          Hi Neil,

          Neil Fleming wrote:
          > --- Paul Beskeen <yahoo@...> wrote:
          >> Hi Neil,
          >>
          >> 1) I don't understand what benefit you would get if
          >> you continue to save
          >> in sRGB colour space (as suggested by your workflow)
          >> but with "color
          >> profile" ticked. The default for all browsers is
          >> sRGB.
          >
          > Think of it this way. The sRGB color space represents
          > the range of values that you *can* work with. Like
          > the range of choices on a bingo card.
          >
          > Unless you are viewing an image with the color profile
          > embedded, *and* your program will accommodate that
          > mapping, you will see "uncontrolled" results rather
          > than that the author intended. "B5" on your bingo
          > card could be "B7" on another's.
          >
          > Just take a look at the ICC example in the original
          > e-mail. The authors picked (on purpose) an extreme
          > example, but it illustrates the point well.

          I don't mean to be argumentative here, and I'm certainly no expert in
          colour management, but I guess it comes down to the question "do ICC
          aware applications by default gamut map to sRGB whether or not the image
          is tagged as sRGB?". [The default for browsers, monitors, HDTV's, etc is
          to use sRGB colour space. Most don't succeed very well so calibration is
          advisable for accurate display]

          If the person viewing your image has profiled their monitor, then the
          graphic card LUT tables will be set at startup to adjust to the correct
          gamma and white point. If a program is ICC enabled then in addition
          gamut mapping will be used to render the image's colours correctly based
          on its tagged colour profile, or (and this may be were we differ) if no
          profile information exists in the image, as sRGB.

          Ahh, this "Web Browser Color Management Tutorial" page is *very*
          informative:
          http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#

          In amongst all the other goodies it has a roll over graphic of an sRGB
          tagged and untagged image. I can discern no difference between the two -
          so Firefox3 defaults to assuming an sRGB profile. However... when I try
          the same with Safari I can see a subtle difference! So Safari doesn't do
          sRGB gamut mapping unless it is tagged as sRGB! From comments on the
          page it appears that Vista's new colour management system also
          automatically defaults to sRGB if an image is not tagged. Given that
          sRGB is the standard for the web I'm surprised that Safari doesn't sRGB
          map unless the image is tagged as such.

          Bottom line: Tagging as sRGB certainly does no harm and in some
          circumstances can lead to a more accurate rendering. Your advice is
          completely correct :)

          >> 2) If you save in an alternative colour space - such
          >> as Adobe RGB, then
          >> won't people without ICC enabled browsers see some
          >> very strange effects?
          >
          > I wouldn't necessarily call it "extreme", but there
          > would be minor differences. Adobe RGB is better
          > adapted to printing, with its wider gamut than sRGB.
          > Some of the colors would be shifted to something you
          > can see. What you see on your monitor would not what
          > would be printed, unless you have a high-end monitor
          > like an Eizo, one that is capable of displaying the
          > full Adobe 1998 gamut.

          Tagging images for web display with anything other than sRGB should
          definitely be avoided. The vast majority of web browsers are not colour
          managed & displays not profiled - an image that uses AdobeRGB or any
          profile other than sRGB will definitely render incorrectly.

          To demonstrate this issue go to the section "ADOBE RGB (1998) 2.2
          gamma", and try the rollover graphic.
          http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#

          Cheers, Paul.

          > ...Neil
          >
          > www.flemingastrophotography.com
          > Direct from Boston - brilliant diamonds in pea soup
          > Also check out the astro_narrowband Yahoo group!
        • sc02492
          Excellent post, and I completely agree. I made the point on another website that I could see no difference in my own astroimages on my website (processed in
          Message 4 of 15 , Jul 2, 2008
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            Excellent post, and I completely agree. I made the point on another
            website that I could see no difference in my own astroimages on my
            website (processed in sRBG space, which most of us do), whether or not
            color management was activated in Firefox 3. Certainly for other
            color spaces like Adobe RGB, a color managed browser would be useful,
            but most of us don't process in Adobe RGB color space. Paul makes the
            excellent point that tagging an astroimage in anything other than sRGB
            color space should be avoided, since it will introduce even more
            variability in how our astroimages appear to others, unless everyone
            decides to use a color managed browser.

            That said, all of the images on my website are indeed tagged with sRGB
            profiles- this has been my practice all along, the main reason being
            that if anyone wanted to open an image in Photoshop, I wanted to
            ensure that it looked the same to them (assuming that their monitor is
            well calibrated). But if there is also a minor benefit to tagging an
            image in sRGB color space, with respect to viewing it in a web
            browser, it certainly will do no harm to include it (see end of post
            to determine if it makes a difference for you).

            Since I cannot see a difference in astroimaging sites with color
            management turned on or off, I'm keeping mine off for now (Firefox 3).
            The performance hit with color management turned on, no matter how
            small, is irritating to me since the images themselves look no
            different on my monitor. However, I would advise people to see for
            themselves whether astroimages on various websites look different on
            their own monitors, and do whatever they think is best. Don't assume
            anything until you've tried it. You can feel free to use my website
            as a test, since I can assure you that all of the images were
            processed in sRGB color space.

            Finally, people may find this useful to test their own system. Here
            is one of my own images, processed in sRGB color space in Photoshop
            but uploaded untagged:
            http://www.starrywonders.com/rosettewithoutICCsRGB.jpg

            And here is the same image with an embedded sRGB profile tag:
            http://www.starrywonders.com/rosettewithICCsRGB.jpg

            With color management turned OFF, open them side by side to see if
            there is a difference, and then you can assess this more objectively.
            Again, this may be monitor and OS dependent, so your mileage may
            vary, but it wouldn't surprise me if most see no appreciable difference.

            Steve


            Steve Cannistra
            http://www.starrywonders.com

            --- In ccd-newastro@yahoogroups.com, Paul Beskeen <yahoo@...> wrote:
            >
            > Hi Neil,
            >
            > Neil Fleming wrote:
            > > --- Paul Beskeen <yahoo@...> wrote:
            > >> Hi Neil,
            > >>
            > >> 1) I don't understand what benefit you would get if
            > >> you continue to save
            > >> in sRGB colour space (as suggested by your workflow)
            > >> but with "color
            > >> profile" ticked. The default for all browsers is
            > >> sRGB.
            > >
            > > Think of it this way. The sRGB color space represents
            > > the range of values that you *can* work with. Like
            > > the range of choices on a bingo card.
            > >
            > > Unless you are viewing an image with the color profile
            > > embedded, *and* your program will accommodate that
            > > mapping, you will see "uncontrolled" results rather
            > > than that the author intended. "B5" on your bingo
            > > card could be "B7" on another's.
            > >
            > > Just take a look at the ICC example in the original
            > > e-mail. The authors picked (on purpose) an extreme
            > > example, but it illustrates the point well.
            >
            > I don't mean to be argumentative here, and I'm certainly no expert in
            > colour management, but I guess it comes down to the question "do ICC
            > aware applications by default gamut map to sRGB whether or not the
            image
            > is tagged as sRGB?". [The default for browsers, monitors, HDTV's,
            etc is
            > to use sRGB colour space. Most don't succeed very well so
            calibration is
            > advisable for accurate display]
            >
            > If the person viewing your image has profiled their monitor, then the
            > graphic card LUT tables will be set at startup to adjust to the correct
            > gamma and white point. If a program is ICC enabled then in addition
            > gamut mapping will be used to render the image's colours correctly
            based
            > on its tagged colour profile, or (and this may be were we differ) if no
            > profile information exists in the image, as sRGB.
            >
            > Ahh, this "Web Browser Color Management Tutorial" page is *very*
            > informative:
            >
            http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
            >
            > In amongst all the other goodies it has a roll over graphic of an sRGB
            > tagged and untagged image. I can discern no difference between the
            two -
            > so Firefox3 defaults to assuming an sRGB profile. However... when I try
            > the same with Safari I can see a subtle difference! So Safari
            doesn't do
            > sRGB gamut mapping unless it is tagged as sRGB! From comments on the
            > page it appears that Vista's new colour management system also
            > automatically defaults to sRGB if an image is not tagged. Given that
            > sRGB is the standard for the web I'm surprised that Safari doesn't sRGB
            > map unless the image is tagged as such.
            >
            > Bottom line: Tagging as sRGB certainly does no harm and in some
            > circumstances can lead to a more accurate rendering. Your advice is
            > completely correct :)
            >
            > >> 2) If you save in an alternative colour space - such
            > >> as Adobe RGB, then
            > >> won't people without ICC enabled browsers see some
            > >> very strange effects?
            > >
            > > I wouldn't necessarily call it "extreme", but there
            > > would be minor differences. Adobe RGB is better
            > > adapted to printing, with its wider gamut than sRGB.
            > > Some of the colors would be shifted to something you
            > > can see. What you see on your monitor would not what
            > > would be printed, unless you have a high-end monitor
            > > like an Eizo, one that is capable of displaying the
            > > full Adobe 1998 gamut.
            >
            > Tagging images for web display with anything other than sRGB should
            > definitely be avoided. The vast majority of web browsers are not colour
            > managed & displays not profiled - an image that uses AdobeRGB or any
            > profile other than sRGB will definitely render incorrectly.
            >
            > To demonstrate this issue go to the section "ADOBE RGB (1998) 2.2
            > gamma", and try the rollover graphic.
            >
            http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
            >
            > Cheers, Paul.
            >
            > > ...Neil
            > >
            > > www.flemingastrophotography.com
            > > Direct from Boston - brilliant diamonds in pea soup
            > > Also check out the astro_narrowband Yahoo group!
            >
          • sc02492
            Sorry, Freudian slip : With color management turned OFF, open them side by side to see if there is a difference, and then you can assess this more
            Message 5 of 15 , Jul 2, 2008
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              Sorry, Freudian slip <g>:

              "With color management turned OFF, open them side by side to see if
              there is a difference, and then you can assess this more objectively."

              I obviously meant with color management turned ON. Sorry to confuse.

              Steve


              --- In ccd-newastro@yahoogroups.com, "sc02492" <sc02492@...> wrote:
              >
              > Excellent post, and I completely agree. I made the point on another
              > website that I could see no difference in my own astroimages on my
              > website (processed in sRBG space, which most of us do), whether or not
              > color management was activated in Firefox 3. Certainly for other
              > color spaces like Adobe RGB, a color managed browser would be useful,
              > but most of us don't process in Adobe RGB color space. Paul makes the
              > excellent point that tagging an astroimage in anything other than sRGB
              > color space should be avoided, since it will introduce even more
              > variability in how our astroimages appear to others, unless everyone
              > decides to use a color managed browser.
              >
              > That said, all of the images on my website are indeed tagged with sRGB
              > profiles- this has been my practice all along, the main reason being
              > that if anyone wanted to open an image in Photoshop, I wanted to
              > ensure that it looked the same to them (assuming that their monitor is
              > well calibrated). But if there is also a minor benefit to tagging an
              > image in sRGB color space, with respect to viewing it in a web
              > browser, it certainly will do no harm to include it (see end of post
              > to determine if it makes a difference for you).
              >
              > Since I cannot see a difference in astroimaging sites with color
              > management turned on or off, I'm keeping mine off for now (Firefox 3).
              > The performance hit with color management turned on, no matter how
              > small, is irritating to me since the images themselves look no
              > different on my monitor. However, I would advise people to see for
              > themselves whether astroimages on various websites look different on
              > their own monitors, and do whatever they think is best. Don't assume
              > anything until you've tried it. You can feel free to use my website
              > as a test, since I can assure you that all of the images were
              > processed in sRGB color space.
              >
              > Finally, people may find this useful to test their own system. Here
              > is one of my own images, processed in sRGB color space in Photoshop
              > but uploaded untagged:
              > http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
              >
              > And here is the same image with an embedded sRGB profile tag:
              > http://www.starrywonders.com/rosettewithICCsRGB.jpg
              >
              > With color management turned OFF, open them side by side to see if
              > there is a difference, and then you can assess this more objectively.
              > Again, this may be monitor and OS dependent, so your mileage may
              > vary, but it wouldn't surprise me if most see no appreciable difference.
              >
              > Steve
              >
              >
              > Steve Cannistra
              > http://www.starrywonders.com
              >
              > --- In ccd-newastro@yahoogroups.com, Paul Beskeen <yahoo@> wrote:
              > >
              > > Hi Neil,
              > >
              > > Neil Fleming wrote:
              > > > --- Paul Beskeen <yahoo@> wrote:
              > > >> Hi Neil,
              > > >>
              > > >> 1) I don't understand what benefit you would get if
              > > >> you continue to save
              > > >> in sRGB colour space (as suggested by your workflow)
              > > >> but with "color
              > > >> profile" ticked. The default for all browsers is
              > > >> sRGB.
              > > >
              > > > Think of it this way. The sRGB color space represents
              > > > the range of values that you *can* work with. Like
              > > > the range of choices on a bingo card.
              > > >
              > > > Unless you are viewing an image with the color profile
              > > > embedded, *and* your program will accommodate that
              > > > mapping, you will see "uncontrolled" results rather
              > > > than that the author intended. "B5" on your bingo
              > > > card could be "B7" on another's.
              > > >
              > > > Just take a look at the ICC example in the original
              > > > e-mail. The authors picked (on purpose) an extreme
              > > > example, but it illustrates the point well.
              > >
              > > I don't mean to be argumentative here, and I'm certainly no expert in
              > > colour management, but I guess it comes down to the question "do ICC
              > > aware applications by default gamut map to sRGB whether or not the
              > image
              > > is tagged as sRGB?". [The default for browsers, monitors, HDTV's,
              > etc is
              > > to use sRGB colour space. Most don't succeed very well so
              > calibration is
              > > advisable for accurate display]
              > >
              > > If the person viewing your image has profiled their monitor, then the
              > > graphic card LUT tables will be set at startup to adjust to the
              correct
              > > gamma and white point. If a program is ICC enabled then in addition
              > > gamut mapping will be used to render the image's colours correctly
              > based
              > > on its tagged colour profile, or (and this may be were we differ)
              if no
              > > profile information exists in the image, as sRGB.
              > >
              > > Ahh, this "Web Browser Color Management Tutorial" page is *very*
              > > informative:
              > >
              >
              http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
              > >
              > > In amongst all the other goodies it has a roll over graphic of an
              sRGB
              > > tagged and untagged image. I can discern no difference between the
              > two -
              > > so Firefox3 defaults to assuming an sRGB profile. However... when
              I try
              > > the same with Safari I can see a subtle difference! So Safari
              > doesn't do
              > > sRGB gamut mapping unless it is tagged as sRGB! From comments on the
              > > page it appears that Vista's new colour management system also
              > > automatically defaults to sRGB if an image is not tagged. Given that
              > > sRGB is the standard for the web I'm surprised that Safari doesn't
              sRGB
              > > map unless the image is tagged as such.
              > >
              > > Bottom line: Tagging as sRGB certainly does no harm and in some
              > > circumstances can lead to a more accurate rendering. Your advice is
              > > completely correct :)
              > >
              > > >> 2) If you save in an alternative colour space - such
              > > >> as Adobe RGB, then
              > > >> won't people without ICC enabled browsers see some
              > > >> very strange effects?
              > > >
              > > > I wouldn't necessarily call it "extreme", but there
              > > > would be minor differences. Adobe RGB is better
              > > > adapted to printing, with its wider gamut than sRGB.
              > > > Some of the colors would be shifted to something you
              > > > can see. What you see on your monitor would not what
              > > > would be printed, unless you have a high-end monitor
              > > > like an Eizo, one that is capable of displaying the
              > > > full Adobe 1998 gamut.
              > >
              > > Tagging images for web display with anything other than sRGB should
              > > definitely be avoided. The vast majority of web browsers are not
              colour
              > > managed & displays not profiled - an image that uses AdobeRGB or any
              > > profile other than sRGB will definitely render incorrectly.
              > >
              > > To demonstrate this issue go to the section "ADOBE RGB (1998) 2.2
              > > gamma", and try the rollover graphic.
              > >
              >
              http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
              > >
              > > Cheers, Paul.
              > >
              > > > ...Neil
              > > >
              > > > www.flemingastrophotography.com
              > > > Direct from Boston - brilliant diamonds in pea soup
              > > > Also check out the astro_narrowband Yahoo group!
              > >
              >
            • Neil Fleming
              I see only subtle differences on my current monitor, Steve. I suspect that would change from monitor-to-monitor, though. I wonder if the perfomance impact
              Message 6 of 15 , Jul 2, 2008
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                I see only subtle differences on my current monitor,
                Steve. I suspect that would change from
                monitor-to-monitor, though.

                I wonder if the "perfomance impact" is due to some
                additional download requirements due to the profile
                being embedded, or to the interpretation of the ICC
                profile once downloaded. The former, I would guess.

                ...Neil

                --- sc02492 <sc02492@...> wrote:

                > Sorry, Freudian slip <g>:
                >
                > "With color management turned OFF, open them side by
                > side to see if
                > there is a difference, and then you can assess this
                > more objectively."
                >
                > I obviously meant with color management turned ON.
                > Sorry to confuse.
                >
                > Steve
                >
                > --- In ccd-newastro@yahoogroups.com, "sc02492"
                > <sc02492@...> wrote:
                > >
                > > Excellent post, and I completely agree. I made
                > the point on another
                > > website that I could see no difference in my own
                > astroimages on my
                > > website (processed in sRBG space, which most of us
                > do), whether or not
                > > color management was activated in Firefox 3.
                > Certainly for other
                > > color spaces like Adobe RGB, a color managed
                > browser would be useful,
                > > but most of us don't process in Adobe RGB color
                > space. Paul makes the
                > > excellent point that tagging an astroimage in
                > anything other than sRGB
                > > color space should be avoided, since it will
                > introduce even more
                > > variability in how our astroimages appear to
                > others, unless everyone
                > > decides to use a color managed browser.
                > >
                > > That said, all of the images on my website are
                > indeed tagged with sRGB
                > > profiles- this has been my practice all along, the
                > main reason being
                > > that if anyone wanted to open an image in
                > Photoshop, I wanted to
                > > ensure that it looked the same to them (assuming
                > that their monitor is
                > > well calibrated). But if there is also a minor
                > benefit to tagging an
                > > image in sRGB color space, with respect to viewing
                > it in a web
                > > browser, it certainly will do no harm to include
                > it (see end of post
                > > to determine if it makes a difference for you).
                > >
                > > Since I cannot see a difference in astroimaging
                > sites with color
                > > management turned on or off, I'm keeping mine off
                > for now (Firefox 3).
                > > The performance hit with color management turned
                > on, no matter how
                > > small, is irritating to me since the images
                > themselves look no
                > > different on my monitor. However, I would advise
                > people to see for
                > > themselves whether astroimages on various websites
                > look different on
                > > their own monitors, and do whatever they think is
                > best. Don't assume
                > > anything until you've tried it. You can feel free
                > to use my website
                > > as a test, since I can assure you that all of the
                > images were
                > > processed in sRGB color space.
                > >
                > > Finally, people may find this useful to test their
                > own system. Here
                > > is one of my own images, processed in sRGB color
                > space in Photoshop
                > > but uploaded untagged:
                > >
                >
                http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
                > >
                > > And here is the same image with an embedded sRGB
                > profile tag:
                > >
                > http://www.starrywonders.com/rosettewithICCsRGB.jpg
                > >
                > > With color management turned OFF, open them side
                > by side to see if
                > > there is a difference, and then you can assess
                > this more objectively.
                > > Again, this may be monitor and OS dependent, so
                > your mileage may
                > > vary, but it wouldn't surprise me if most see no
                > appreciable difference.
                > >
                > > Steve
                > >
                > >
                > > Steve Cannistra
                > > http://www.starrywonders.com
                > >
                > > --- In ccd-newastro@yahoogroups.com, Paul Beskeen
                > <yahoo@> wrote:
                > > >
                > > > Hi Neil,
                > > >
                > > > Neil Fleming wrote:
                > > > > --- Paul Beskeen <yahoo@> wrote:
                > > > >> Hi Neil,
                > > > >>
                > > > >> 1) I don't understand what benefit you would
                > get if
                > > > >> you continue to save
                > > > >> in sRGB colour space (as suggested by your
                > workflow)
                > > > >> but with "color
                > > > >> profile" ticked. The default for all browsers
                > is
                > > > >> sRGB.
                > > > >
                > > > > Think of it this way. The sRGB color space
                > represents
                > > > > the range of values that you *can* work with.
                > Like
                > > > > the range of choices on a bingo card.
                > > > >
                > > > > Unless you are viewing an image with the color
                > profile
                > > > > embedded, *and* your program will accommodate
                > that
                > > > > mapping, you will see "uncontrolled" results
                > rather
                > > > > than that the author intended. "B5" on your
                > bingo
                > > > > card could be "B7" on another's.
                > > > >
                > > > > Just take a look at the ICC example in the
                > original
                > > > > e-mail. The authors picked (on purpose) an
                > extreme
                > > > > example, but it illustrates the point well.
                > > >
                > > > I don't mean to be argumentative here, and I'm
                > certainly no expert in
                > > > colour management, but I guess it comes down to
                > the question "do ICC
                > > > aware applications by default gamut map to sRGB
                > whether or not the
                > > image
                > > > is tagged as sRGB?". [The default for browsers,
                > monitors, HDTV's,
                > > etc is
                > > > to use sRGB colour space. Most don't succeed
                > very well so
                > > calibration is
                > > > advisable for accurate display]
                > > >
                > > > If the person viewing your image has profiled
                > their monitor, then the
                > > > graphic card LUT tables will be set at startup
                > to adjust to the
                > correct
                > > > gamma and white point. If a program is ICC
                > enabled then in addition
                > > > gamut mapping will be used to render the image's
                > colours correctly
                > > based
                > > > on its tagged colour profile, or (and this may
                > be were we differ)
                > if no
                > > > profile information exists in the image, as
                > sRGB.
                > > >
                > > > Ahh, this "Web Browser Color Management
                > Tutorial" page is *very*
                > > > informative:
                > > >
                > >
                >
                http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
                > > >
                > > > In amongst all the other goodies it has a roll
                > over graphic of an
                > sRGB
                > > > tagged and untagged image. I can discern no
                > difference between the
                > > two -
                > > > so Firefox3 defaults to assuming an sRGB
                > profile. However... when
                > I try
                > > > the same with Safari I can see a subtle
                > difference! So Safari
                > > doesn't do
                > > > sRGB gamut mapping unless it is tagged as sRGB!
                > From comments on the
                > > > page it appears that Vista's new colour
                > management system also
                > > > automatically defaults to sRGB if an image is
                > not tagged. Given that
                > > > sRGB is the standard for the web I'm surprised
                > that Safari doesn't
                > sRGB
                > > > map unless the image is tagged as such.
                >
                === message truncated ===


                www.flemingastrophotography.com
                Direct from Boston - brilliant diamonds in pea soup
                Also check out the astro_narrowband Yahoo group!
              • sc02492
                Neil, that s a good question- I don t know, but if you look at the size difference between the embedded versus non-embedded image, it is minor. So perhaps
                Message 7 of 15 , Jul 2, 2008
                • 0 Attachment
                  Neil, that's a good question- I don't know, but if you look at the
                  size difference between the embedded versus non-embedded image, it is
                  minor. So perhaps it's some sort of processing/interpretation of the
                  ICC profile?

                  Steve

                  --- In ccd-newastro@yahoogroups.com, Neil Fleming <neilfleming@...> wrote:
                  >
                  > I see only subtle differences on my current monitor,
                  > Steve. I suspect that would change from
                  > monitor-to-monitor, though.
                  >
                  > I wonder if the "perfomance impact" is due to some
                  > additional download requirements due to the profile
                  > being embedded, or to the interpretation of the ICC
                  > profile once downloaded. The former, I would guess.
                  >
                  > ...Neil
                  >
                  > --- sc02492 <sc02492@...> wrote:
                  >
                  > > Sorry, Freudian slip <g>:
                  > >
                  > > "With color management turned OFF, open them side by
                  > > side to see if
                  > > there is a difference, and then you can assess this
                  > > more objectively."
                  > >
                  > > I obviously meant with color management turned ON.
                  > > Sorry to confuse.
                  > >
                  > > Steve
                  > >
                  > > --- In ccd-newastro@yahoogroups.com, "sc02492"
                  > > <sc02492@> wrote:
                  > > >
                  > > > Excellent post, and I completely agree. I made
                  > > the point on another
                  > > > website that I could see no difference in my own
                  > > astroimages on my
                  > > > website (processed in sRBG space, which most of us
                  > > do), whether or not
                  > > > color management was activated in Firefox 3.
                  > > Certainly for other
                  > > > color spaces like Adobe RGB, a color managed
                  > > browser would be useful,
                  > > > but most of us don't process in Adobe RGB color
                  > > space. Paul makes the
                  > > > excellent point that tagging an astroimage in
                  > > anything other than sRGB
                  > > > color space should be avoided, since it will
                  > > introduce even more
                  > > > variability in how our astroimages appear to
                  > > others, unless everyone
                  > > > decides to use a color managed browser.
                  > > >
                  > > > That said, all of the images on my website are
                  > > indeed tagged with sRGB
                  > > > profiles- this has been my practice all along, the
                  > > main reason being
                  > > > that if anyone wanted to open an image in
                  > > Photoshop, I wanted to
                  > > > ensure that it looked the same to them (assuming
                  > > that their monitor is
                  > > > well calibrated). But if there is also a minor
                  > > benefit to tagging an
                  > > > image in sRGB color space, with respect to viewing
                  > > it in a web
                  > > > browser, it certainly will do no harm to include
                  > > it (see end of post
                  > > > to determine if it makes a difference for you).
                  > > >
                  > > > Since I cannot see a difference in astroimaging
                  > > sites with color
                  > > > management turned on or off, I'm keeping mine off
                  > > for now (Firefox 3).
                  > > > The performance hit with color management turned
                  > > on, no matter how
                  > > > small, is irritating to me since the images
                  > > themselves look no
                  > > > different on my monitor. However, I would advise
                  > > people to see for
                  > > > themselves whether astroimages on various websites
                  > > look different on
                  > > > their own monitors, and do whatever they think is
                  > > best. Don't assume
                  > > > anything until you've tried it. You can feel free
                  > > to use my website
                  > > > as a test, since I can assure you that all of the
                  > > images were
                  > > > processed in sRGB color space.
                  > > >
                  > > > Finally, people may find this useful to test their
                  > > own system. Here
                  > > > is one of my own images, processed in sRGB color
                  > > space in Photoshop
                  > > > but uploaded untagged:
                  > > >
                  > >
                  > http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
                  > > >
                  > > > And here is the same image with an embedded sRGB
                  > > profile tag:
                  > > >
                  > > http://www.starrywonders.com/rosettewithICCsRGB.jpg
                  > > >
                  > > > With color management turned OFF, open them side
                  > > by side to see if
                  > > > there is a difference, and then you can assess
                  > > this more objectively.
                  > > > Again, this may be monitor and OS dependent, so
                  > > your mileage may
                  > > > vary, but it wouldn't surprise me if most see no
                  > > appreciable difference.
                  > > >
                  > > > Steve
                  > > >
                  > > >
                  > > > Steve Cannistra
                  > > > http://www.starrywonders.com
                  > > >
                  > > > --- In ccd-newastro@yahoogroups.com, Paul Beskeen
                  > > <yahoo@> wrote:
                  > > > >
                  > > > > Hi Neil,
                  > > > >
                  > > > > Neil Fleming wrote:
                  > > > > > --- Paul Beskeen <yahoo@> wrote:
                  > > > > >> Hi Neil,
                  > > > > >>
                  > > > > >> 1) I don't understand what benefit you would
                  > > get if
                  > > > > >> you continue to save
                  > > > > >> in sRGB colour space (as suggested by your
                  > > workflow)
                  > > > > >> but with "color
                  > > > > >> profile" ticked. The default for all browsers
                  > > is
                  > > > > >> sRGB.
                  > > > > >
                  > > > > > Think of it this way. The sRGB color space
                  > > represents
                  > > > > > the range of values that you *can* work with.
                  > > Like
                  > > > > > the range of choices on a bingo card.
                  > > > > >
                  > > > > > Unless you are viewing an image with the color
                  > > profile
                  > > > > > embedded, *and* your program will accommodate
                  > > that
                  > > > > > mapping, you will see "uncontrolled" results
                  > > rather
                  > > > > > than that the author intended. "B5" on your
                  > > bingo
                  > > > > > card could be "B7" on another's.
                  > > > > >
                  > > > > > Just take a look at the ICC example in the
                  > > original
                  > > > > > e-mail. The authors picked (on purpose) an
                  > > extreme
                  > > > > > example, but it illustrates the point well.
                  > > > >
                  > > > > I don't mean to be argumentative here, and I'm
                  > > certainly no expert in
                  > > > > colour management, but I guess it comes down to
                  > > the question "do ICC
                  > > > > aware applications by default gamut map to sRGB
                  > > whether or not the
                  > > > image
                  > > > > is tagged as sRGB?". [The default for browsers,
                  > > monitors, HDTV's,
                  > > > etc is
                  > > > > to use sRGB colour space. Most don't succeed
                  > > very well so
                  > > > calibration is
                  > > > > advisable for accurate display]
                  > > > >
                  > > > > If the person viewing your image has profiled
                  > > their monitor, then the
                  > > > > graphic card LUT tables will be set at startup
                  > > to adjust to the
                  > > correct
                  > > > > gamma and white point. If a program is ICC
                  > > enabled then in addition
                  > > > > gamut mapping will be used to render the image's
                  > > colours correctly
                  > > > based
                  > > > > on its tagged colour profile, or (and this may
                  > > be were we differ)
                  > > if no
                  > > > > profile information exists in the image, as
                  > > sRGB.
                  > > > >
                  > > > > Ahh, this "Web Browser Color Management
                  > > Tutorial" page is *very*
                  > > > > informative:
                  > > > >
                  > > >
                  > >
                  >
                  http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
                  > > > >
                  > > > > In amongst all the other goodies it has a roll
                  > > over graphic of an
                  > > sRGB
                  > > > > tagged and untagged image. I can discern no
                  > > difference between the
                  > > > two -
                  > > > > so Firefox3 defaults to assuming an sRGB
                  > > profile. However... when
                  > > I try
                  > > > > the same with Safari I can see a subtle
                  > > difference! So Safari
                  > > > doesn't do
                  > > > > sRGB gamut mapping unless it is tagged as sRGB!
                  > > From comments on the
                  > > > > page it appears that Vista's new colour
                  > > management system also
                  > > > > automatically defaults to sRGB if an image is
                  > > not tagged. Given that
                  > > > > sRGB is the standard for the web I'm surprised
                  > > that Safari doesn't
                  > > sRGB
                  > > > > map unless the image is tagged as such.
                  > >
                  > === message truncated ===
                  >
                  >
                  > www.flemingastrophotography.com
                  > Direct from Boston - brilliant diamonds in pea soup
                  > Also check out the astro_narrowband Yahoo group!
                  >
                • Bill Bradford
                  Hi Paul, I did as you said and did the rollovers on the link you provided. And, sure enough, my newly installed FF3 showed the colors properly. That s a great
                  Message 8 of 15 , Jul 2, 2008
                  • 0 Attachment
                    Hi Paul,
                    I did as you said and did the rollovers on the link you provided. And, sure
                    enough, my newly installed FF3 showed the colors properly.

                    That's a great site and it is going to take me awhile to digest all the
                    information but it will be a good
                    learning experience for me.

                    Thanks for posting it,
                    Bill
                    ----- Original Message -----
                    From: "Paul Beskeen" <yahoo@...>
                    To: <ccd-newastro@yahoogroups.com>
                    Sent: Wednesday, July 02, 2008 9:32 AM
                    Subject: Re: [ccd-newastro] Full Write-up on Embedding the ICC Color Profile
                    into our Jpgs


                    > Hi Neil,
                    >
                    > Neil Fleming wrote:
                    >> --- Paul Beskeen <yahoo@...> wrote:
                    >>> Hi Neil,
                    >>>
                    >>> 1) I don't understand what benefit you would get if
                    >>> you continue to save
                    >>> in sRGB colour space (as suggested by your workflow)
                    >>> but with "color
                    >>> profile" ticked. The default for all browsers is
                    >>> sRGB.
                    >>
                    >> Think of it this way. The sRGB color space represents
                    >> the range of values that you *can* work with. Like
                    >> the range of choices on a bingo card.
                    >>
                    >> Unless you are viewing an image with the color profile
                    >> embedded, *and* your program will accommodate that
                    >> mapping, you will see "uncontrolled" results rather
                    >> than that the author intended. "B5" on your bingo
                    >> card could be "B7" on another's.
                    >>
                    >> Just take a look at the ICC example in the original
                    >> e-mail. The authors picked (on purpose) an extreme
                    >> example, but it illustrates the point well.
                    >
                    > I don't mean to be argumentative here, and I'm certainly no expert in
                    > colour management, but I guess it comes down to the question "do ICC
                    > aware applications by default gamut map to sRGB whether or not the image
                    > is tagged as sRGB?". [The default for browsers, monitors, HDTV's, etc is
                    > to use sRGB colour space. Most don't succeed very well so calibration is
                    > advisable for accurate display]
                    >
                    > If the person viewing your image has profiled their monitor, then the
                    > graphic card LUT tables will be set at startup to adjust to the correct
                    > gamma and white point. If a program is ICC enabled then in addition
                    > gamut mapping will be used to render the image's colours correctly based
                    > on its tagged colour profile, or (and this may be were we differ) if no
                    > profile information exists in the image, as sRGB.
                    >
                    > Ahh, this "Web Browser Color Management Tutorial" page is *very*
                    > informative:
                    > http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
                    >
                    > In amongst all the other goodies it has a roll over graphic of an sRGB
                    > tagged and untagged image. I can discern no difference between the two -
                    > so Firefox3 defaults to assuming an sRGB profile. However... when I try
                    > the same with Safari I can see a subtle difference! So Safari doesn't do
                    > sRGB gamut mapping unless it is tagged as sRGB! From comments on the
                    > page it appears that Vista's new colour management system also
                    > automatically defaults to sRGB if an image is not tagged. Given that
                    > sRGB is the standard for the web I'm surprised that Safari doesn't sRGB
                    > map unless the image is tagged as such.
                    >
                    > Bottom line: Tagging as sRGB certainly does no harm and in some
                    > circumstances can lead to a more accurate rendering. Your advice is
                    > completely correct :)
                    >
                    >>> 2) If you save in an alternative colour space - such
                    >>> as Adobe RGB, then
                    >>> won't people without ICC enabled browsers see some
                    >>> very strange effects?
                    >>
                    >> I wouldn't necessarily call it "extreme", but there
                    >> would be minor differences. Adobe RGB is better
                    >> adapted to printing, with its wider gamut than sRGB.
                    >> Some of the colors would be shifted to something you
                    >> can see. What you see on your monitor would not what
                    >> would be printed, unless you have a high-end monitor
                    >> like an Eizo, one that is capable of displaying the
                    >> full Adobe 1998 gamut.
                    >
                    > Tagging images for web display with anything other than sRGB should
                    > definitely be avoided. The vast majority of web browsers are not colour
                    > managed & displays not profiled - an image that uses AdobeRGB or any
                    > profile other than sRGB will definitely render incorrectly.
                    >
                    > To demonstrate this issue go to the section "ADOBE RGB (1998) 2.2
                    > gamma", and try the rollover graphic.
                    > http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#
                    >
                    > Cheers, Paul.
                    >
                    >> ...Neil
                    >>
                    >> www.flemingastrophotography.com
                    >> Direct from Boston - brilliant diamonds in pea soup
                    >> Also check out the astro_narrowband Yahoo group!
                    >
                    > ------------------------------------
                    >
                    >
                    >
                    >
                  • Rainer
                    Hi Neil, Thanks. Now If I understood correctly when you open Photoshop you are using as working space sRGB ? FRam what I knoe about Color Management that is
                    Message 9 of 15 , Jul 3, 2008
                    • 0 Attachment
                      Hi Neil,

                      Thanks. Now If I understood correctly when you open Photoshop you are
                      using as working space sRGB ?

                      FRam what I knoe about Color Management that is not a good idea. It
                      is better to use a working space similar tothe one your monitor is
                      able to display and that in most cases is AdobeRGB or maybe BETA RGB
                      or Pro Photo color space.

                      If you already open you images in sRGB you already clipped some
                      colors due to the fact that you are squeezing your image into that
                      color space.

                      From my point of view it is alaway best to use as much colors as you
                      can when you process your images. As last step as you say you convert
                      (not assign) the finished image into sRGB

                      Microsoft has a nice little application where you can compare in 3D
                      the different color spaces and so you can see which color space is
                      wider and which one is narrower.

                      Here is the link for the download

                      http://www.softpedia.com/get/System/OS-Enhancements/Microsoft-Color\
                      -Control-Panel-Applet-for-Windows-XP.shtml

                      This is very interesting.

                      regards Rainer




                      >
                      > Neil, that's a good question- I don't know, but if you look at the
                      > size difference between the embedded versus non-embedded image, it
                      is
                      > minor. So perhaps it's some sort of processing/interpretation of
                      the
                      > ICC profile?
                      >
                      > Steve
                      >
                      > --- In ccd-newastro@yahoogroups.com, Neil Fleming <neilfleming@>
                      wrote:
                      > >
                      > > I see only subtle differences on my current monitor,
                      > > Steve. I suspect that would change from
                      > > monitor-to-monitor, though.
                      > >
                      > > I wonder if the "perfomance impact" is due to some
                      > > additional download requirements due to the profile
                      > > being embedded, or to the interpretation of the ICC
                      > > profile once downloaded. The former, I would guess.
                      > >
                      > > ...Neil
                      > >
                      > > --- sc02492 <sc02492@> wrote:
                      > >
                      > > > Sorry, Freudian slip <g>:
                      > > >
                      > > > "With color management turned OFF, open them side by
                      > > > side to see if
                      > > > there is a difference, and then you can assess this
                      > > > more objectively."
                      > > >
                      > > > I obviously meant with color management turned ON.
                      > > > Sorry to confuse.
                      > > >
                      > > > Steve
                      > > >
                      > > > --- In ccd-newastro@yahoogroups.com, "sc02492"
                      > > > <sc02492@> wrote:
                      > > > >
                      > > > > Excellent post, and I completely agree. I made
                      > > > the point on another
                      > > > > website that I could see no difference in my own
                      > > > astroimages on my
                      > > > > website (processed in sRBG space, which most of us
                      > > > do), whether or not
                      > > > > color management was activated in Firefox 3.
                      > > > Certainly for other
                      > > > > color spaces like Adobe RGB, a color managed
                      > > > browser would be useful,
                      > > > > but most of us don't process in Adobe RGB color
                      > > > space. Paul makes the
                      > > > > excellent point that tagging an astroimage in
                      > > > anything other than sRGB
                      > > > > color space should be avoided, since it will
                      > > > introduce even more
                      > > > > variability in how our astroimages appear to
                      > > > others, unless everyone
                      > > > > decides to use a color managed browser.
                      > > > >
                      > > > > That said, all of the images on my website are
                      > > > indeed tagged with sRGB
                      > > > > profiles- this has been my practice all along, the
                      > > > main reason being
                      > > > > that if anyone wanted to open an image in
                      > > > Photoshop, I wanted to
                      > > > > ensure that it looked the same to them (assuming
                      > > > that their monitor is
                      > > > > well calibrated). But if there is also a minor
                      > > > benefit to tagging an
                      > > > > image in sRGB color space, with respect to viewing
                      > > > it in a web
                      > > > > browser, it certainly will do no harm to include
                      > > > it (see end of post
                      > > > > to determine if it makes a difference for you).
                      > > > >
                      > > > > Since I cannot see a difference in astroimaging
                      > > > sites with color
                      > > > > management turned on or off, I'm keeping mine off
                      > > > for now (Firefox 3).
                      > > > > The performance hit with color management turned
                      > > > on, no matter how
                      > > > > small, is irritating to me since the images
                      > > > themselves look no
                      > > > > different on my monitor. However, I would advise
                      > > > people to see for
                      > > > > themselves whether astroimages on various websites
                      > > > look different on
                      > > > > their own monitors, and do whatever they think is
                      > > > best. Don't assume
                      > > > > anything until you've tried it. You can feel free
                      > > > to use my website
                      > > > > as a test, since I can assure you that all of the
                      > > > images were
                      > > > > processed in sRGB color space.
                      > > > >
                      > > > > Finally, people may find this useful to test their
                      > > > own system. Here
                      > > > > is one of my own images, processed in sRGB color
                      > > > space in Photoshop
                      > > > > but uploaded untagged:
                      > > > >
                      > > >
                      > > http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
                      > > > >
                      > > > > And here is the same image with an embedded sRGB
                      > > > profile tag:
                      > > > >
                      > > > http://www.starrywonders.com/rosettewithICCsRGB.jpg
                      > > > >
                      > > > > With color management turned OFF, open them side
                      > > > by side to see if
                      > > > > there is a difference, and then you can assess
                      > > > this more objectively.
                      > > > > Again, this may be monitor and OS dependent, so
                      > > > your mileage may
                      > > > > vary, but it wouldn't surprise me if most see no
                      > > > appreciable difference.
                      > > > >
                      > > > > Steve
                      > > > >
                      > > > >
                      > > > > Steve Cannistra
                      > > > > http://www.starrywonders.com
                      > > > >
                      > > > > --- In ccd-newastro@yahoogroups.com, Paul Beskeen
                      > > > <yahoo@> wrote:
                      > > > > >
                      > > > > > Hi Neil,
                      > > > > >
                      > > > > > Neil Fleming wrote:
                      > > > > > > --- Paul Beskeen <yahoo@> wrote:
                      > > > > > >> Hi Neil,
                      > > > > > >>
                      > > > > > >> 1) I don't understand what benefit you would
                      > > > get if
                      > > > > > >> you continue to save
                      > > > > > >> in sRGB colour space (as suggested by your
                      > > > workflow)
                      > > > > > >> but with "color
                      > > > > > >> profile" ticked. The default for all browsers
                      > > > is
                      > > > > > >> sRGB.
                      > > > > > >
                      > > > > > > Think of it this way. The sRGB color space
                      > > > represents
                      > > > > > > the range of values that you *can* work with.
                      > > > Like
                      > > > > > > the range of choices on a bingo card.
                      > > > > > >
                      > > > > > > Unless you are viewing an image with the color
                      > > > profile
                      > > > > > > embedded, *and* your program will accommodate
                      > > > that
                      > > > > > > mapping, you will see "uncontrolled" results
                      > > > rather
                      > > > > > > than that the author intended. "B5" on your
                      > > > bingo
                      > > > > > > card could be "B7" on another's.
                      > > > > > >
                      > > > > > > Just take a look at the ICC example in the
                      > > > original
                      > > > > > > e-mail. The authors picked (on purpose) an
                      > > > extreme
                      > > > > > > example, but it illustrates the point well.
                      > > > > >
                      > > > > > I don't mean to be argumentative here, and I'm
                      > > > certainly no expert in
                      > > > > > colour management, but I guess it comes down to
                      > > > the question "do ICC
                      > > > > > aware applications by default gamut map to sRGB
                      > > > whether or not the
                      > > > > image
                      > > > > > is tagged as sRGB?". [The default for browsers,
                      > > > monitors, HDTV's,
                      > > > > etc is
                      > > > > > to use sRGB colour space. Most don't succeed
                      > > > very well so
                      > > > > calibration is
                      > > > > > advisable for accurate display]
                      > > > > >
                      > > > > > If the person viewing your image has profiled
                      > > > their monitor, then the
                      > > > > > graphic card LUT tables will be set at startup
                      > > > to adjust to the
                      > > > correct
                      > > > > > gamma and white point. If a program is ICC
                      > > > enabled then in addition
                      > > > > > gamut mapping will be used to render the image's
                      > > > colours correctly
                      > > > > based
                      > > > > > on its tagged colour profile, or (and this may
                      > > > be were we differ)
                      > > > if no
                      > > > > > profile information exists in the image, as
                      > > > sRGB.
                      > > > > >
                      > > > > > Ahh, this "Web Browser Color Management
                      > > > Tutorial" page is *very*
                      > > > > > informative:
                      > > > > >
                      > > > >
                      > > >
                      > >
                      >
                      http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.
                      html#
                      > > > > >
                      > > > > > In amongst all the other goodies it has a roll
                      > > > over graphic of an
                      > > > sRGB
                      > > > > > tagged and untagged image. I can discern no
                      > > > difference between the
                      > > > > two -
                      > > > > > so Firefox3 defaults to assuming an sRGB
                      > > > profile. However... when
                      > > > I try
                      > > > > > the same with Safari I can see a subtle
                      > > > difference! So Safari
                      > > > > doesn't do
                      > > > > > sRGB gamut mapping unless it is tagged as sRGB!
                      > > > From comments on the
                      > > > > > page it appears that Vista's new colour
                      > > > management system also
                      > > > > > automatically defaults to sRGB if an image is
                      > > > not tagged. Given that
                      > > > > > sRGB is the standard for the web I'm surprised
                      > > > that Safari doesn't
                      > > > sRGB
                      > > > > > map unless the image is tagged as such.
                      > > >
                      > > === message truncated ===
                      > >
                      > >
                      > > www.flemingastrophotography.com
                      > > Direct from Boston - brilliant diamonds in pea soup
                      > > Also check out the astro_narrowband Yahoo group!
                      > >
                      >
                    • Rainer
                      Addendum: If you want to put a icon on your desktop you will find the executable file WinColor.exe in the following directory C: Program Files Pro Imaging
                      Message 10 of 15 , Jul 3, 2008
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                        Addendum:

                        If you want to put a icon on your desktop you will find the
                        executable file

                        WinColor.exe

                        in the following directory

                        C:\Program Files\Pro Imaging Powertoys\Microsoft Color Control Panel
                        Applet for Windows XP

                        regards Rainer






                        > Hi Neil,
                        >
                        > Thanks. Now If I understood correctly when you open Photoshop you
                        are
                        > using as working space sRGB ?
                        >
                        > FRam what I knoe about Color Management that is not a good idea. It
                        > is better to use a working space similar tothe one your monitor is
                        > able to display and that in most cases is AdobeRGB or maybe BETA
                        RGB
                        > or Pro Photo color space.
                        >
                        > If you already open you images in sRGB you already clipped some
                        > colors due to the fact that you are squeezing your image into that
                        > color space.
                        >
                        > From my point of view it is alaway best to use as much colors as
                        you
                        > can when you process your images. As last step as you say you
                        convert
                        > (not assign) the finished image into sRGB
                        >
                        > Microsoft has a nice little application where you can compare in 3D
                        > the different color spaces and so you can see which color space is
                        > wider and which one is narrower.
                        >
                        > Here is the link for the download
                        >
                        > http://www.softpedia.com/get/System/OS-Enhancements/Microsoft-Color\
                        > -Control-Panel-Applet-for-Windows-XP.shtml
                        >
                        > This is very interesting.
                        >
                        > regards Rainer
                        >
                        >
                        >
                        >
                        > >
                        > > Neil, that's a good question- I don't know, but if you look at the
                        > > size difference between the embedded versus non-embedded image,
                        it
                        > is
                        > > minor. So perhaps it's some sort of processing/interpretation of
                        > the
                        > > ICC profile?
                        > >
                        > > Steve
                        > >
                        > > --- In ccd-newastro@yahoogroups.com, Neil Fleming <neilfleming@>
                        > wrote:
                        > > >
                        > > > I see only subtle differences on my current monitor,
                        > > > Steve. I suspect that would change from
                        > > > monitor-to-monitor, though.
                        > > >
                        > > > I wonder if the "perfomance impact" is due to some
                        > > > additional download requirements due to the profile
                        > > > being embedded, or to the interpretation of the ICC
                        > > > profile once downloaded. The former, I would guess.
                        > > >
                        > > > ...Neil
                        > > >
                        > > > --- sc02492 <sc02492@> wrote:
                        > > >
                        > > > > Sorry, Freudian slip <g>:
                        > > > >
                        > > > > "With color management turned OFF, open them side by
                        > > > > side to see if
                        > > > > there is a difference, and then you can assess this
                        > > > > more objectively."
                        > > > >
                        > > > > I obviously meant with color management turned ON.
                        > > > > Sorry to confuse.
                        > > > >
                        > > > > Steve
                        > > > >
                        > > > > --- In ccd-newastro@yahoogroups.com, "sc02492"
                        > > > > <sc02492@> wrote:
                        > > > > >
                        > > > > > Excellent post, and I completely agree. I made
                        > > > > the point on another
                        > > > > > website that I could see no difference in my own
                        > > > > astroimages on my
                        > > > > > website (processed in sRBG space, which most of us
                        > > > > do), whether or not
                        > > > > > color management was activated in Firefox 3.
                        > > > > Certainly for other
                        > > > > > color spaces like Adobe RGB, a color managed
                        > > > > browser would be useful,
                        > > > > > but most of us don't process in Adobe RGB color
                        > > > > space. Paul makes the
                        > > > > > excellent point that tagging an astroimage in
                        > > > > anything other than sRGB
                        > > > > > color space should be avoided, since it will
                        > > > > introduce even more
                        > > > > > variability in how our astroimages appear to
                        > > > > others, unless everyone
                        > > > > > decides to use a color managed browser.
                        > > > > >
                        > > > > > That said, all of the images on my website are
                        > > > > indeed tagged with sRGB
                        > > > > > profiles- this has been my practice all along, the
                        > > > > main reason being
                        > > > > > that if anyone wanted to open an image in
                        > > > > Photoshop, I wanted to
                        > > > > > ensure that it looked the same to them (assuming
                        > > > > that their monitor is
                        > > > > > well calibrated). But if there is also a minor
                        > > > > benefit to tagging an
                        > > > > > image in sRGB color space, with respect to viewing
                        > > > > it in a web
                        > > > > > browser, it certainly will do no harm to include
                        > > > > it (see end of post
                        > > > > > to determine if it makes a difference for you).
                        > > > > >
                        > > > > > Since I cannot see a difference in astroimaging
                        > > > > sites with color
                        > > > > > management turned on or off, I'm keeping mine off
                        > > > > for now (Firefox 3).
                        > > > > > The performance hit with color management turned
                        > > > > on, no matter how
                        > > > > > small, is irritating to me since the images
                        > > > > themselves look no
                        > > > > > different on my monitor. However, I would advise
                        > > > > people to see for
                        > > > > > themselves whether astroimages on various websites
                        > > > > look different on
                        > > > > > their own monitors, and do whatever they think is
                        > > > > best. Don't assume
                        > > > > > anything until you've tried it. You can feel free
                        > > > > to use my website
                        > > > > > as a test, since I can assure you that all of the
                        > > > > images were
                        > > > > > processed in sRGB color space.
                        > > > > >
                        > > > > > Finally, people may find this useful to test their
                        > > > > own system. Here
                        > > > > > is one of my own images, processed in sRGB color
                        > > > > space in Photoshop
                        > > > > > but uploaded untagged:
                        > > > > >
                        > > > >
                        > > > http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
                        > > > > >
                        > > > > > And here is the same image with an embedded sRGB
                        > > > > profile tag:
                        > > > > >
                        > > > > http://www.starrywonders.com/rosettewithICCsRGB.jpg
                        > > > > >
                        > > > > > With color management turned OFF, open them side
                        > > > > by side to see if
                        > > > > > there is a difference, and then you can assess
                        > > > > this more objectively.
                        > > > > > Again, this may be monitor and OS dependent, so
                        > > > > your mileage may
                        > > > > > vary, but it wouldn't surprise me if most see no
                        > > > > appreciable difference.
                        > > > > >
                        > > > > > Steve
                        > > > > >
                        > > > > >
                        > > > > > Steve Cannistra
                        > > > > > http://www.starrywonders.com
                        > > > > >
                        > > > > > --- In ccd-newastro@yahoogroups.com, Paul Beskeen
                        > > > > <yahoo@> wrote:
                        > > > > > >
                        > > > > > > Hi Neil,
                        > > > > > >
                        > > > > > > Neil Fleming wrote:
                        > > > > > > > --- Paul Beskeen <yahoo@> wrote:
                        > > > > > > >> Hi Neil,
                        > > > > > > >>
                        > > > > > > >> 1) I don't understand what benefit you would
                        > > > > get if
                        > > > > > > >> you continue to save
                        > > > > > > >> in sRGB colour space (as suggested by your
                        > > > > workflow)
                        > > > > > > >> but with "color
                        > > > > > > >> profile" ticked. The default for all browsers
                        > > > > is
                        > > > > > > >> sRGB.
                        > > > > > > >
                        > > > > > > > Think of it this way. The sRGB color space
                        > > > > represents
                        > > > > > > > the range of values that you *can* work with.
                        > > > > Like
                        > > > > > > > the range of choices on a bingo card.
                        > > > > > > >
                        > > > > > > > Unless you are viewing an image with the color
                        > > > > profile
                        > > > > > > > embedded, *and* your program will accommodate
                        > > > > that
                        > > > > > > > mapping, you will see "uncontrolled" results
                        > > > > rather
                        > > > > > > > than that the author intended. "B5" on your
                        > > > > bingo
                        > > > > > > > card could be "B7" on another's.
                        > > > > > > >
                        > > > > > > > Just take a look at the ICC example in the
                        > > > > original
                        > > > > > > > e-mail. The authors picked (on purpose) an
                        > > > > extreme
                        > > > > > > > example, but it illustrates the point well.
                        > > > > > >
                        > > > > > > I don't mean to be argumentative here, and I'm
                        > > > > certainly no expert in
                        > > > > > > colour management, but I guess it comes down to
                        > > > > the question "do ICC
                        > > > > > > aware applications by default gamut map to sRGB
                        > > > > whether or not the
                        > > > > > image
                        > > > > > > is tagged as sRGB?". [The default for browsers,
                        > > > > monitors, HDTV's,
                        > > > > > etc is
                        > > > > > > to use sRGB colour space. Most don't succeed
                        > > > > very well so
                        > > > > > calibration is
                        > > > > > > advisable for accurate display]
                        > > > > > >
                        > > > > > > If the person viewing your image has profiled
                        > > > > their monitor, then the
                        > > > > > > graphic card LUT tables will be set at startup
                        > > > > to adjust to the
                        > > > > correct
                        > > > > > > gamma and white point. If a program is ICC
                        > > > > enabled then in addition
                        > > > > > > gamut mapping will be used to render the image's
                        > > > > colours correctly
                        > > > > > based
                        > > > > > > on its tagged colour profile, or (and this may
                        > > > > be were we differ)
                        > > > > if no
                        > > > > > > profile information exists in the image, as
                        > > > > sRGB.
                        > > > > > >
                        > > > > > > Ahh, this "Web Browser Color Management
                        > > > > Tutorial" page is *very*
                        > > > > > > informative:
                        > > > > > >
                        > > > > >
                        > > > >
                        > > >
                        > >
                        >
                        http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.
                        > html#
                        > > > > > >
                        > > > > > > In amongst all the other goodies it has a roll
                        > > > > over graphic of an
                        > > > > sRGB
                        > > > > > > tagged and untagged image. I can discern no
                        > > > > difference between the
                        > > > > > two -
                        > > > > > > so Firefox3 defaults to assuming an sRGB
                        > > > > profile. However... when
                        > > > > I try
                        > > > > > > the same with Safari I can see a subtle
                        > > > > difference! So Safari
                        > > > > > doesn't do
                        > > > > > > sRGB gamut mapping unless it is tagged as sRGB!
                        > > > > From comments on the
                        > > > > > > page it appears that Vista's new colour
                        > > > > management system also
                        > > > > > > automatically defaults to sRGB if an image is
                        > > > > not tagged. Given that
                        > > > > > > sRGB is the standard for the web I'm surprised
                        > > > > that Safari doesn't
                        > > > > sRGB
                        > > > > > > map unless the image is tagged as such.
                        > > > >
                        > > > === message truncated ===
                        > > >
                        > > >
                        > > > www.flemingastrophotography.com
                        > > > Direct from Boston - brilliant diamonds in pea soup
                        > > > Also check out the astro_narrowband Yahoo group!
                        > > >
                        > >
                        >
                      • Sander Pool
                        These looked identical in FF3 with default color management settings (ie. off) on my system with just a plain jane Samsung 940b flat screen. Rainer wrote that
                        Message 11 of 15 , Jul 3, 2008
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                          These looked identical in FF3 with default color management settings
                          (ie. off) on my system with just a plain jane Samsung 940b flat screen.

                          Rainer wrote that AdobeRGB would be better than sRGB. It would be
                          interesting to see this illustrated.

                          Thanks,

                          Sander

                          PS making sure I always include the color profile from now on

                          Steve wrote:
                          Finally, people may find this useful to test their own system. Here
                          is one of my own images, processed in sRGB color space in Photoshop
                          but uploaded untagged:
                          http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
                          <http://www.starrywonders.com/rosettewithoutICCsRGB.jpg>

                          And here is the same image with an embedded sRGB profile tag:
                          http://www.starrywonders.com/rosettewithICCsRGB.jpg
                          <http://www.starrywonders.com/rosettewithICCsRGB.jpg>

                          With color management turned OFF, open them side by side to see if
                          there is a difference, and then you can assess this more objectively.
                          Again, this may be monitor and OS dependent, so your mileage may
                          vary, but it wouldn't surprise me if most see no appreciable difference.
                        • Rainer
                          Hi Sander, If you download the WinColor.exe prgram you can play around yourself and there you can see that the Adobe RGB color space is far wider then the sRGB
                          Message 12 of 15 , Jul 4, 2008
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                            Hi Sander,

                            If you download the WinColor.exe prgram you can play around yourself
                            and there you can see that the Adobe RGB color space is far wider then
                            the sRGB color space

                            Here take a look at the screenshot

                            http://rainerehlert.com/adobe/CM-ARGB-SRGB.jpg

                            The outer space is Adobe RGB and the inner space is sRGB. It is easier
                            to understand if you use WinColor.exe by yourself as you could also
                            look at your monitor capable color space and comprare it to sRGB or
                            AdobeRGB.

                            This image for example

                            http://rainerehlert.com/adobe/CM-ARGB-monitor.jpg

                            shows the color space of my monitor inside of Adobe RGB.

                            regards Rainer


                            >
                            >
                            > These looked identical in FF3 with default color management settings
                            > (ie. off) on my system with just a plain jane Samsung 940b flat screen.
                            >
                            > Rainer wrote that AdobeRGB would be better than sRGB. It would be
                            > interesting to see this illustrated.
                            >
                            > Thanks,
                            >
                            > Sander
                            >
                            > PS making sure I always include the color profile from now on
                            >
                            > Steve wrote:
                            > Finally, people may find this useful to test their own system. Here
                            > is one of my own images, processed in sRGB color space in Photoshop
                            > but uploaded untagged:
                            > http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
                            > <http://www.starrywonders.com/rosettewithoutICCsRGB.jpg>
                            >
                            > And here is the same image with an embedded sRGB profile tag:
                            > http://www.starrywonders.com/rosettewithICCsRGB.jpg
                            > <http://www.starrywonders.com/rosettewithICCsRGB.jpg>
                            >
                            > With color management turned OFF, open them side by side to see if
                            > there is a difference, and then you can assess this more objectively.
                            > Again, this may be monitor and OS dependent, so your mileage may
                            > vary, but it wouldn't surprise me if most see no appreciable difference.
                            >
                          • Neil Fleming
                            Rainer, I ve been thinking about your statements re clipping data if working in sRGB versus a wider gamut. So, I asked one of the most authoritative gents I
                            Message 13 of 15 , Jul 4, 2008
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                              Rainer, I've been thinking about your statements re
                              clipping data if working in sRGB versus a wider gamut.
                              So, I asked one of the most authoritative gents I
                              know in this area, and here is what he had to say:

                              > From: "Noel Carboni" <NCarboni@...>
                              >
                              > Think not in terms of gamut - but in terms of
                              > absolute R, G, B values.
                              >
                              > Your editors manipulate the R, G, B values, and your
                              > histograms tell you
                              > whether you're clipping (i.e., you'll see data jam
                              > up against the ends).
                              >
                              > How that data is rendered in the end - e.g., how red
                              > does a R,G,B value of
                              > 255,0,0 look on the screen - is determined by the
                              > color space choice. It
                              > makes no difference during the editing what space
                              > you're working in as long
                              > as you don't jam against the ends.
                              >
                              > Using the highest possible bit depth (e.g., 16 with
                              > Photoshop today,
                              > practically speaking) ensures that you don't
                              > introduce much inaccuracy.
                              >
                              > So... Stretch/open so that the data is not clipped
                              > on either end (I find
                              > FITS Liberator's math functions good for this), edit
                              > in 16 bit mode and
                              > watch your histograms, and voila, you can edit in
                              > sRGB and lose nothing.
                              >
                              > -Noel
                              >
                              > --- Noel Carboni <NCarboni@...> wrote:
                              >
                              > > Hi Neil,
                              > >
                              > > Not unless you clip the black or white levels.
                              > >
                              > > As long as you watch the histograms and avoid
                              > operations that clip I'd
                              > > say you're generally better off working in sRGB
                              > format, since your
                              > > images will display equally well in
                              > non-color-managed applications.
                              > >
                              > > Keep this in mind: People who equate "greater
                              > gamut" with "better"
                              > > are oversimplifying things.
                              > >
                              > > The funny thing is that most computer displays and
                              > printers are built
                              > > to handle no more than the sRGB gamut anyway.
                              > >
                              > > The best new monitors actually often do exceed the
                              > gamut provided by
                              > > sRGB, but it really doesn't matter that much -
                              > we're not portraying
                              > > astro objects in accurate color anyway. To
                              > oversimplify things a bit
                              > > myself, gamut is almost meaningless with
                              > astroimagery.
                              > >
                              > > As with most things, there's no one absolutely
                              > best way to do things,
                              > > but if you avoid clipping black and white levels
                              > while processing, you
                              > > really can't go wrong using sRGB. If you *do*
                              > really want to use a
                              > > color space with a wider gamut, and you understand
                              > why, don't stop at
                              > > Adobe RGB; use the ProPhoto color space, which has
                              > the widest gamut of
                              > > all.
                              > >
                              > > -Noel


                              www.flemingastrophotography.com
                              Direct from Boston - brilliant diamonds in pea soup
                              Also check out the astro_narrowband Yahoo group!
                            • Neil Fleming
                              You might have seen the note I got from Noel on the topic by now, Sander. He argues, and I think it makes sense, that the color space choice impacts the
                              Message 14 of 15 , Jul 4, 2008
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                                You might have seen the note I got from Noel on the
                                topic by now, Sander. He argues, and I think it makes
                                sense, that the color space choice impacts the
                                *presentation* of the underlying data only. As long
                                as we don't clip the ends of the histograms, there is
                                no data clipping inherent in selecting one color space
                                over another. It merely influences which RGB values
                                are sent to the screen for color presentation
                                purposes.

                                Interesting topic, though.

                                ...Neil

                                --- Sander Pool <sander@...> wrote:
                                >
                                > These looked identical in FF3 with default color
                                > management settings
                                > (ie. off) on my system with just a plain jane
                                > Samsung 940b flat screen.
                                >
                                > Rainer wrote that AdobeRGB would be better than
                                > sRGB. It would be
                                > interesting to see this illustrated.
                                >
                                > Thanks,
                                >
                                > Sander
                                >
                                > PS making sure I always include the color profile
                                > from now on
                                >
                                > Steve wrote:
                                > Finally, people may find this useful to test their
                                > own system. Here
                                > is one of my own images, processed in sRGB color
                                > space in Photoshop
                                > but uploaded untagged:
                                >
                                http://www.starrywonders.com/rosettewithoutICCsRGB.jpg
                                >
                                >
                                <http://www.starrywonders.com/rosettewithoutICCsRGB.jpg>
                                >
                                > And here is the same image with an embedded sRGB
                                > profile tag:
                                > http://www.starrywonders.com/rosettewithICCsRGB.jpg
                                >
                                <http://www.starrywonders.com/rosettewithICCsRGB.jpg>
                                >
                                > With color management turned OFF, open them side by
                                > side to see if
                                > there is a difference, and then you can assess this
                                > more objectively.
                                > Again, this may be monitor and OS dependent, so your
                                > mileage may
                                > vary, but it wouldn't surprise me if most see no
                                > appreciable difference.
                                >


                                www.flemingastrophotography.com
                                Direct from Boston - brilliant diamonds in pea soup
                                Also check out the astro_narrowband Yahoo group!
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