I work in a VFX adjacent space, so I have some pretty strong feelings about what data should be stored in the colorspace tags. The colorspace data should be an

I work in a VFX adjacent space, so I have some pretty strong feelings about what data should be stored in the colorspace tags. The colorspace data should be an arbitrary string. I would also like to have "usage intent" tag for whether this is color or non-color data. You would think that the colorspace would tell you, but people do silly things like save specular maps as sRGB. For completeness I would want the following fields: - colorspace - arbitrary string, the colorspace of the color data on disk. - rgb_primaries - arbitrary string, indicates the physical meaning of the linear RGB values. - transfer_function - arbitrary string, indicates the function to use to linearise the values from disk into the RGB primaries. - intent - one of display, texture, data, or an arbitrary string. Display images get tone-mapped, textures do not, data only gets linearised, even if it has rgb_primaries attached, other values only have internal meaning to the concrete art pipeline. For the first three, rgb_primaries and transfer_function take precedence over colorspace. The reason I want them is because people do mix and match. You could say that you can put the same data in some string format in the colorspace tag, but then everyone will invent their own slightly different way of specifying it and interoperability will suffer. Best to just force the values to be unstructured. A lot of arbitrary strings, but that's how it is - there is really no standard list of colorspace names. These four fields can cover pretty much everything I have seen people do. Though currently a lot of people just tag the filename with a colorspace suffix and call it a day. OpenColorIO even has a function to directly get a colorspace from a filename.