QuickTime Color Representation in AVIFs/HEIFs

[blue-j]

Hey there,

I have a decoding for this field, if useful.  Presently, the field quicktime:colorrepresentation outputs values like this:

quicktime:colorrepresentation   nclx 9 16 10

Those 4 values are independent.  They are kind of part of a struct, with a cardinality of 1.

So, "Color Profiles" in these files are

nclx
rICC
prof

or not present.

Then the three integers following signify "Color Primaries," "Transfer Characteristics" and "Matrix Coefficients."

Please find attached the decoding key.

References:

https://aomediacodec.github.io/av1-spec/av1-spec.pdf

https://www.digikam.org/api/heif_8h_source.html
Lines 573 - 702

[Phil Harvey]

Thanks.  ExifTool 12.45 will add a set of conversions for these tags.

- Phil