Embedded color profiles not applied

[automata]

Original image: https://the-grid-user-content.s3-us-west-2.amazonaws.com/baa20170-30cb-4b91-b6e4-e2fb23f85201.jpg

After passthrough graph: https://s3-us-west-2.amazonaws.com/the-grid-img/p/5441a8fdc92d4c7462f0dec49eeea876a23086a9.jpg

Debug: https://imgflo.herokuapp.com/debug/graph/851b8fd15e770b1/82f7417a607d155cc609b573de658c54/passthrough.jpg/?input=https%3A%2F%2Fthe-grid-user-content.s3-us-west-2.amazonaws.com%2Fbaa20170-30cb-4b91-b6e4-e2fb23f85201.jpg&width=720&debug=1

Image have different sizes, maybe JPEG compression?

[jonnor]

@automata where/how do they differ on your device? Can you screenshot side-by-side?

On my Android phone I am unable to discern any difference. Which may mean this is about color management (or rather, lack thereof).

[forresto]

Smells like color space issue:

Original:

WARNING: Embedded color profile: “(unrecognized embedded color profile 'ProPhoto RGB')”

http://regex.info/exif.cgi?imgurl=https%3A%2F%2Fthe-grid-user-content.s3-us-west-2.amazonaws.com%2Fbaa20170-30cb-4b91-b6e4-e2fb23f85201.jpg

imgflo passthrough:

WARNING: No color-space metadata and no embedded color profile: Windows and Mac web browsers treat colors randomly.

http://regex.info/exif.cgi?dummy=on&imgurl=https%3A%2F%2Fs3-us-west-2.amazonaws.com%2Fthe-grid-img%2Fp%2F5441a8fdc92d4c7462f0dec49eeea876a23086a9.jpg

[forresto]

(original left passthrough right)

[forresto]

Interesting... Android original looks like Mac passthrough.

@jonnor can passthrough pass through the color space metadata? There will still be discrepancies across systems, but at least on the same device it will be the same.

[jonnor]

The output image is a new image, and there is no facilities in GEGL atm for tracking colorspace through the processing pipeline. But preprocessor to extract color profile and then reinserting into output image would be possible.
It would however leave browsers without color management support (like Chrome on Android) with bland colors.
Alternative is to convert to sRGB when reading the input. That would make it look the same on all browsers. However on high-end displays where CM is supported the images may be duller than possible, because the smaller gamut of sRGB clips possible outputs.