How to assign KHR_DF_PRIMARIES_UNSPECIFIED? (v4.3 alpha)

[donmccurdy]

Hi! I'm testing out the v4.3 alpha. In previous versions I'd specify --assign_primaries none for non-color textures being converted, e.g. from PNG to UASTC. There doesn't appear to be any equivalent value for the --assign-primaries now, is that intended? I'm not sure that color space data in the source PNG is reliable, and so would like to ensure this is set correctly in the KTX2 output.

[MarkCallow]

@vadery, please answer this and update the documentation so it is clear.

[aqnuep]

Indeed, there's no equivalent of KHR_DF_PRIMARIES_UNSPECIFIED as a value for --assign-primaries. This wasn't called out as a requirement, but I see how that could be a problem if the input file contains incorrect information about color primaries.

There are some interactions to be considered from testing perspective, but it should be easy to add a none option. We'll look into this.