AdobeRGB to sRGB

  • Thread starter Thread starter Guillaume Dargaud
  • Start date Start date
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Guillaume Dargaud

I've recently learned to use color management, including the supposedly
better AdobeRGB profile. All fine once the whole chain is properly setup,
but what if you want to distribute the images to non experts, for instance
to put them up on the web or on CDs ? Browsers don't handle embedded
profiles, so the bit values should be converted to sRGB and the profiles
just removed. Right ?
Is there a utility that can batch scan this process ?
 
Guillaume Dargaud said:
I've recently learned to use color management, including the supposedly
better AdobeRGB profile. All fine once the whole chain is properly setup,
but what if you want to distribute the images to non experts, for instance
to put them up on the web or on CDs ? Browsers don't handle embedded
profiles, so the bit values should be converted to sRGB and the profiles
just removed. Right ?
Is there a utility that can batch scan this process ?
Click to expand...


I've been told that modern browsers do in fact honor
profile tags, but I'm not sure how to verify that.

The conventional wisdom is that web graphics should
be in sRGB space. I'm not aware of any utilites to do
this, other than Photoshop. I'm sure it must exist...


rafe b
www.terrapinphoto.com
 
SNIP
Browsers don't handle embedded profiles,
Click to expand...

I believe the Mac Browser does. Current Windows explorer doesn't, so
it is safest to convert to sRGB (because there are few displays that
cover the entire Adobe RGB gamut).
so the bit values should be converted to sRGB and the profiles just
removed. Right ?
Correct.

Is there a utility that can batch scan this process ?
Click to expand...

Photoshop can do the conversions ("Save for Web" removes the profile),
and ImageMagick can do that. If you want to scan *and* batch process
at the same time, then VueScan would be able to do that, if your
scanner is supported.
 
Recently said:
SNIP

I believe the Mac Browser does. Current Windows explorer doesn't, so
it is safest to convert to sRGB (because there are few displays that
cover the entire Adobe RGB gamut).
Click to expand...
On a PC, the ability to use embedded profiles is determined by the video
card & drivers. For example, with many Matrox cards (as well as other
makes), one can set a desired profile for the card. Whether the monitor is
up to the task, of course depends on its capabilities. There is no
shortage of monitor/card combinations for the PC that are capable of
displaying AdobeRGB as well as those for the Mac, and I'd suspect that in
this ng, there would be a good number of participants whose systems are
capable. That said, the mass of users on the web do not have graphics
systems, and therefore a good web design will stay within the sRGB color
gamut.

Regards,

Neil
 
As long as the image is in a format supported by the second party's viewer
(e.g. jpeg, tif) the embedded profile matters naught.
Color gamut issues for web sites can be significant for commercial vendors
but are not a major issue for amateur sites-your image is going to be down
converted to a usable form by whatever automated program you use to make
your web page with anyway.
 
As long as the image is in a format supported by the second party's viewer
(e.g. jpeg, tif) the embedded profile matters naught.
Click to expand...


Eh? You've really quite lost me here. I checked the Mozilla
FAQs and it appears that Firefox supports embedded profiles
in both JPGs and TIFs, on both Mac and Win platforms.

<http://www.mozilla.org/projects/colorsync/>

It looks like IE (for Mac) does also, but I haven't been
able to verify one way or another if Windoze IE does...
Color gamut issues for web sites can be significant for commercial vendors
but are not a major issue for amateur sites-your image is going to be down
converted to a usable form by whatever automated program you use to make
your web page with anyway.
Click to expand...


Eh? My web site consists of HTML, CSS and JPGs
(oh, and one TIFF, just for Don.)

Nothing processes the JPGs. What sort of
"down conversion" are you thinking of?


rafe b
www.terrapinphoto.com
 
SNIP
It looks like IE (for Mac) does also, but I haven't been
able to verify one way or another if Windoze IE does...
Click to expand...

No, on Windows it doesn't, yet. Maybe an upcoming version 7.+ does,
but since most likely the majority of global browsing is done on IE on
Windows, it is prudent to convert to sRGB. Things are (or should be)
obviously better in specialized calibrated professional environments.

Also, LCD displays are quickly overtaking CRTs on new computer
installations, and most (almost all) natively have a significantly
smaller gamut than Adobe RGB, they are closer to sRGB. They usually
have an even smaller gamut if they are profiled, because unlike CRTs
which can amplify individual channel guns to adjust the whitepoint,
most LCDs can only reduce/filter channel luminocity/saturation to
alter the fixed whitepoint of the backlighting.

If one wants to be in control, rather than leave the profile
conversion (if any) to a mostly Microsoft color engine converting to a
most likely unprofiled LCD under varying viewing conditions, again
convert to sRGB oneself and hope for the best.

Bart
 
As long as the image is in a format supported by the second party's viewer
(e.g. jpeg, tif) the embedded profile matters naught.
Click to expand...
Don't agree. Take an image in AdobeRGB, whose profile is ignored or
overridden by sRGB. Because the RGB numbers in the file now refer to
the R,G,B points of the sRGB gamut, the image will be displayed with
less saturation. Irrespective of the quality of the physical display
device (you can try by displaying the same image, having an AdobeRGB
profile, side by side on the same screen, with two applications that
do/don't manage profiles).
And, an "amateur" may want, e.g. to display a photo gallery.

Bernard
 
I'm a little late to this, but...

Neil said:
On a PC, the ability to use embedded profiles is determined by the video
card & drivers. For example, with many Matrox cards (as well as other
makes), one can set a desired profile for the card. Whether the monitor is
up to the task, of course depends on its capabilities. There is no
Click to expand...

<snip>

That's not entirely accurate. A good display profile is necessary for
truly accurate display of any color-managed image, but the image
viewing or editing software needs to be able to interpret and convert
the image to match the display. Otherwise you're just getting a more
accurate version of the same old unprofiled Windows color space.

Also, some color management approaches directly affect the video
driver's color behavior so that *all* programs will display accurate
Windows colors (but not necessarily respect embedded profiles), whereas
others are internal to a particular program and require only that the
given program be told which profile to use for the display. If both
methods are in effect, the monitor profile used in the internally
color-managed program needs to take the altered system-level colors
into account. But a program like Photoshop can do equally well on its
own by applying a single display profile created *without* any
alterations to the video driver.

That's my understanding, at least. Let me know if I'm wrong. :)

false_dmitrii
 
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