The site mishandles AdobeRGB or ProPhotoRGB profiles

In my brief time here uploading images, I've found that the thumbnail and small place-holder images that the site displays have severe color shift and desaturation if the image is tagged with either AdobeRGB or ProPhotoRGB profiles. No problem if the image has an sRGB profile.

The full size image displays correctly, no matter the profile as that's pulled into one's browser, intact. But since it must have an sRGB profile for the smaller previews to show properly, that severely limits the gamut of images we upload here.

Can the site be upgraded to handle AdobeRGB and ProPhotoRGB profiles? After all, these are "industry-standard" color spaces. sRGB is a joke.

Thanks,

Rich

Thanks!

Rich

Just to be complete, I could be wrong, but it looks like the site isn't responding well to sRGB either. It's just that it's WAY off for files with AdobeRGB and ProPhotoRGB and sort of "default" close to sRGB, but it doesn't really appear to be reading the profile.

Rich

The images I have uploaded so far all look OK. Normally it's the browser that is at fault in these situations.

Are you sure you are using a colour managed browser and that colour management is turned on?

I checked the issue using both Safari and Chrome. On a Mac. And iPhone. Same behavior in each.

I've not run into this kind of problem before. In years.

Is color management something that can be turned on or off in these browsers?

Rich

Chrome has a setting, force-color-profile, you can get to it with this URL: chrome://flags/#force-color-profile. This forces Chrome to use one of the selected profiles from the drop-down to convert images for display. Otherwise, it'll use the OS-provided display profile if available.

Now, for any of the above to work, the image to be displayed has to have a color profile corresponding to the image characteristics embedded in the image metadata. That's the input information for the display transform, and the Chrome-selected profile is the output information. Without either of those, all Chrome knows to do is to blat the image on the display un-transformed. This is what I think is happening to the forum thumbnails - they probably don't have any metadata, let alone the describing color profile.

Yes, it would be good to support these profiles fully.

Thanks for all your hard work.

Don

So, the forum is stripping the profile information from the thumbnail and from the image displayed with the post. And the browser (whatever browser) is doing whatever it can with the RGB values of an untagged file.

Rich

Well, it's not so much 'stripping' as just not carrying it over. The distinction may seem pedantic, but it takes extra programming to compel metadata to follow an image through software.

Edit: I ran across this page some time ago, pretty useful to gain understanding regarding how browsers do (and don't do) color management:

gregbenzphotography.com/photography-tips/how-to-setup-proper-color-management-in-a-web-browser/

Thanks. Didn't know that.

Rich

All of the image formats have some sort of open-source reference implementation of a programming library to read and write them, e.g., libjpeg, libtiff, libpng. Their handling of metadata is a mixed bag, and in every one I've worked with requires manual movement of metadata tags from input to output. Indeed, in the open-source software world the metadata goto is a library called exiv2, and it works as a separate read/write operation from the image read/write.

I can’t say whether or not any are “correct” but all three of the thumbnails are noticeably distinct from one another on my browser. (Safari, iPad OS running the latest public beta.)

Looking good (Ubuntu / Brave)
Thank you!