There's not much information to find online regarding how ImageGen treats color profiles in the images that the users upload. I'm currently working on a project where a photographer uploads JPEG images that have color profiles embedded into them and I use ImageGen Professional to generate all the different sizes needed on the site. If you download/view the original file it looks good, the color profie is intact. But ImageGen seems to remove this profile resulting in images that look strange (people with red faces etc).
I found this thread where there's a discussion about color profiles in PNG images. According to George Gooding in this thread, images served from ImageGen has color profile set to sRGB IEC61966-2. But when we test it by downloading JPEG images generated by ImageGen and opening them up in Photoshop, Photoshop claims they have a color profile which is "untagged RGB".
This leads to some questions:
Is there a difference in how ImageGen works with color profiles depending on which image format you use (JPEG or PNG)?
Does ImageGen use a color profile when generating JPEG images? If so, is it sRGB IEC61966-2 or some other format (untagged RBG)?
If it is sRGB IEC61966-2, how come we get untagged RGB when we open up the images in Photoshop?
I'm also interested in knowing how we can solve this problem? My suggestion so far has been that the photographer converts his images to sRGB IEC61966-2 so there are no other color profiles present in the images before he uploads them. If ImageGen uses sRGB IEC61966-2 as well the conversion should result in no changes in color between the original (uploaded) image and the generated images from ImageGen.
Here's a page with some more background info regarding color management on the web:
I know this is a rather complicated field, especially if you're now a photographer or a graphic designer. To complicate things further, depending on the browser and the monitor you're using, images can look very different.
ImageGen uses sRGB color space for output as this is the most reliable for all web browsers. As a photographer myself it is important that everyone see the best image of my work. While I have color-calibrated monitors and ICC profiles for print I don't rely on those for web display and instead use standard sRGB for web display. The real proof of my work is not on-screen of course but in print, where I am in control of color, gamma, everything. On the web I'm in control of... my screen and my screen only.
You are correct that PNG's specifically set the sRGB IEC61966-2 profile whereas JPG's are not specifically set and are therefore 'untagged' sRGB. I will add that to the todo list. Thanks for pointing it out.
For now, I would ask the photog to use the sRGB space without custom profiles and, if he feels it necessary, display as &format=png to workaround the untagged sRGB space when displayed in the browser.
I've been in contact with the photographer and he claims he "locks" and saves his images in sRGB today (no custom profiles as far as I understand) so it must be the "untagged sRGB" that is served from ImageGen when the format is JPEG that causes the colors to display incorrect on some displays. The original images that have the sRGB profile intact look good.
Do you know when a fix for this could be out? It would be great to know for project planning. The site is due to release in a week or so. Some images are very large and I suspect that we will get a dramatic increase in the number of Kb if we switch to PNG for all images. Haven't tested yet though so I might be wrong. :-)
Doubt there will be a fix before you launch in a week or so. Sadly, you're correct that PNG files are bigger than jpgs, though quality is best with pngs.
One thing you can do that will help some with pngs... after ImageGen creates the PNGs and saves them to the 'cached' folder you can schedule a task to run PNGcrush or a similar utility to smash them even more than ImageGen does. It'll save some kB's and every bit helps.
I would really appreciate it if you could announce this update in some way? We've made an agreement with the client to wait for this update since substituting the JPEG's with PNG's is not an option in our case because of the increased file size.
Any news regarding the sRGB color profile for JPEG's? My client is waiting for some form of feedback regarding this and I would love to be able to give him some positive news.
There's good news -- profiles will be coming! But as we're in the midst of a massive refactoring it will be some time before the new code sees production quality. Will keep you posted.
I saw that you have released a new version of ImageGen (2.9.0). Does this include any changes regarding color profiles? I looked at your blog but couldn't find any information about this.
Sorry, not yet. The security issue required an immediate release so haven't gotten to everything I wanted. Will be keeping at it though with more releases to improve things incrementally.
Is the ImageGen color profile supposed to be sRGB IEC61966-2.1 or not?
There's not much information to find online regarding how ImageGen treats color profiles in the images that the users upload. I'm currently working on a project where a photographer uploads JPEG images that have color profiles embedded into them and I use ImageGen Professional to generate all the different sizes needed on the site. If you download/view the original file it looks good, the color profie is intact. But ImageGen seems to remove this profile resulting in images that look strange (people with red faces etc).
I found this thread where there's a discussion about color profiles in PNG images. According to George Gooding in this thread, images served from ImageGen has color profile set to sRGB IEC61966-2. But when we test it by downloading JPEG images generated by ImageGen and opening them up in Photoshop, Photoshop claims they have a color profile which is "untagged RGB".
This leads to some questions:
Is there a difference in how ImageGen works with color profiles depending on which image format you use (JPEG or PNG)?
Does ImageGen use a color profile when generating JPEG images? If so, is it sRGB IEC61966-2 or some other format (untagged RBG)?
If it is sRGB IEC61966-2, how come we get untagged RGB when we open up the images in Photoshop?
I'm also interested in knowing how we can solve this problem? My suggestion so far has been that the photographer converts his images to sRGB IEC61966-2 so there are no other color profiles present in the images before he uploads them. If ImageGen uses sRGB IEC61966-2 as well the conversion should result in no changes in color between the original (uploaded) image and the generated images from ImageGen.
Here's a page with some more background info regarding color management on the web:
http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html
I know this is a rather complicated field, especially if you're now a photographer or a graphic designer. To complicate things further, depending on the browser and the monitor you're using, images can look very different.
Hi, Thomas,
ImageGen uses sRGB color space for output as this is the most reliable for all web browsers. As a photographer myself it is important that everyone see the best image of my work. While I have color-calibrated monitors and ICC profiles for print I don't rely on those for web display and instead use standard sRGB for web display. The real proof of my work is not on-screen of course but in print, where I am in control of color, gamma, everything. On the web I'm in control of... my screen and my screen only.
You are correct that PNG's specifically set the sRGB IEC61966-2 profile whereas JPG's are not specifically set and are therefore 'untagged' sRGB. I will add that to the todo list. Thanks for pointing it out.
For now, I would ask the photog to use the sRGB space without custom profiles and, if he feels it necessary, display as &format=png to workaround the untagged sRGB space when displayed in the browser.
cheers,
doug.
Hi Doug!
Thanks for a quick reply!
I've been in contact with the photographer and he claims he "locks" and saves his images in sRGB today (no custom profiles as far as I understand) so it must be the "untagged sRGB" that is served from ImageGen when the format is JPEG that causes the colors to display incorrect on some displays. The original images that have the sRGB profile intact look good.
Do you know when a fix for this could be out? It would be great to know for project planning. The site is due to release in a week or so. Some images are very large and I suspect that we will get a dramatic increase in the number of Kb if we switch to PNG for all images. Haven't tested yet though so I might be wrong. :-)
Regards,
Thomas
Doubt there will be a fix before you launch in a week or so. Sadly, you're correct that PNG files are bigger than jpgs, though quality is best with pngs.
One thing you can do that will help some with pngs... after ImageGen creates the PNGs and saves them to the 'cached' folder you can schedule a task to run PNGcrush or a similar utility to smash them even more than ImageGen does. It'll save some kB's and every bit helps.
cheers,
doug.
I would really appreciate it if you could announce this update in some way? We've made an agreement with the client to wait for this update since substituting the JPEG's with PNG's is not an option in our case because of the increased file size.
Thanks in advance!
/Thomas
Hi!
Any news regarding the sRGB color profile for JPEG's?
My client is waiting for some form of feedback regarding this and I would love to be able to give him some positive news.
Regards,
/Thomas
Hi, Thomas,
There's good news -- profiles will be coming! But as we're in the midst of a massive refactoring it will be some time before the new code sees production quality. Will keep you posted.
cheers, doug.
Thanks Doug!
I will notify my client and look forward to the next version!
Regards,
Thomas
Hi!
I saw that you have released a new version of ImageGen (2.9.0). Does this include any changes regarding color profiles? I looked at your blog but couldn't find any information about this.
Thanks in advance!
/Thomas
Sorry, not yet. The security issue required an immediate release so haven't gotten to everything I wanted. Will be keeping at it though with more releases to improve things incrementally.
cheers,
doug.
Okay, thanks!
/Thomas
Hi Douglas!
Is this fixed in 2.9.1?
Sorry, it isn't included as yet.
Is it still on the roadmap?
is working on a reply...