SMPTE ST 2073-4 PDF

This standard extends the Y'C'₁C'₂(A) image format defined in SMPTE ST 2073-3 to include subsampled color difference components (including 4:2:2, 4:2:0, 4:1:1, and 4:1:0). An alpha channel is optional and can have the same resolution as the Y′ channel or the same resolution as the C'₁ and C'₂ channels.

This standard adds the AlphaSampling parameter to specify whether the alpha component is subsampled.

Operations that resample color difference components are out of scope.