US Patent 10136133 Rate control adaptation for high-dynamic range images

A high dynamic range input video signal characterized by either a gamma-based or a perceptually-quantized (PQ) source electro-optical transfer function (EOTF) is to be compressed. Given a luminance range for an image-region in the input, for a gamma-coded input signal, a rate-control adaptation method in the encoder adjusts a region-based quantization parameter (QP) so that it increases in highlight regions and decreases in dark regions, otherwise, for a PQ-coded input, the region-based QP increases in the dark areas and decreases in the highlight areas.