Happy 2021 Everyone
Apologies if this topic has already been covered in other posts.
I’ve been playing around with Siril in Linux Mint for the last few days (v0.99.7 Appimage downloaded from GitLab). The software is fantastic and has amazingly powerful features that could really speed up my processing workflow. However, I have a couple of open questions about Siril’s color management workflow after initial testing.
First, Siril doesn’t seem to transform the image rendered in the RGB preview window from the internal (linear) working space to the color profile of the display, which is sRGB in my case. The result is an image that is rendered much darker than it should be. Changing the display mode from Linear to AutoStretch brightens the image of course, but the tone curve that’s applied isn’t the same as transforming the displayed image to the sRGB color space which has clearly defined primaries and non-linear RGB tone response curves. Is this the intended behavior of the software and if so why?
A second but related issue is that Siril adds an sRGB ICC profile to the metadata of exported tif files but doesn’t transform the image data accordingly. Consequently, images opened in color managed software like GIMP, RawTherapee, Darktable etc using the embedded ICC profile will be rendered incorrectly (too dark). There might also be other consequences for users that further process Siril’s images in these other software depending on which processing modules are used and where they lie in the pixel processing pipeline. Again, is this intended behaviour and if so why?
I know that colour management is tricky topic and difficult to get right so I thought I’d better ask the Siril experts first before I jump to wrong conclusions. Any insights or clarifications are greatly appreciated.
Best regards