US Patent 11172237 Inter-layer dynamic range scalability for HDR video

Methods, processes, and systems are presented for inter-layer scaling and mapping to perform dynamic-range scalability in video coding using single-loop video decoders. Two approaches are proposed: a) A mapping function is applied to each of the color components, b) a mapping function is applied to the luma component and luma-based scaling is applied to the chroma components. Both schemes may be combined with existing schemes for in-loop reshaping, such as luma mapping and chroma residual scaling employed in the versatile video codec (VVC).