Hi there, I’ve used RawTherapee now for over 6 months, and am very happy with the colour results I get both onscreen with my Dell U2711 IPS monitor, and printed on my Canon Pixma iP8760 - one area I’d like to try and improve colour is upload of JPEG’s to Facebook - Facebook recommend saving JPEG’s with an sRGB colour profile, which I’m doing, but none of the included sRGB colour profiles (RTv2_sRGB, RTv4_sRGB, or sRGB) included with RawTherapee seem to work - the vibrant colour’s I see when viewing the local files in any image including the JPEG’s I create to upload, are rendered dull and lifeless once uploaded and viewed on Facebook. It’s as if the saturation has been dropped a lot and contrast have been lowered - quite lifeless looking.
Has anyone else encountered this issue, and if so have you managed to figure out a workflow that lets Facebook at least make some attempt at heeding the inbuilt sRGB colour profile? Facebook does decimate pixel level detail with some overzealous compression, but the colours in other peoples images uploaded from other softwares still seem OK.
While you might be experiencing a color management issue (I can’t say without seeing your before/after photos), your problem might as well be unrelated to color profiles, as there is another issue which affects every uploaded photo. Facebook re-encodes all uploaded images using chroma subsampling and high compression which obliterate all the effort we put into our work. This affects photos with fine color detail more than others. The only solution is to upload your images elsewhere and link them on Facebook.
Ah, and one more thing. As @sankos mentioned, the browser itself could cause problems. To check, simply open your “before” photo in your web browser - no uploading, just open it right from disk. Then in another tab open the photo uploaded to Facebook, and compare.
Yeah, I haven’t seen any serious color issues with RT’s default output settings and posting to Instagram or Facebook with their mobile apps, I’ll double-check Chrome on Linux tonight.
But Morgan is dead on as far as compression artifacts. Facebook destroys image quality. It’s only recently that they added support for images larger than 2000 pixels in any dimension, and 4k is still woefully insufficient for panoramas.