Backward compatible coding for ultra high definition video signals with improved dynamic range

摘要

Video data having both ultra-high definition (UHD) resolution and high or enhanced dynamic range (EDR) data is encoded in a backward-compatible layered stream. This allows legacy decoders to extract HD standard dynamic range (SDR) signals. In response to the base layer HD SDR signal, a predicted signal is generated using separate luma and chroma prediction models. In the luma predictor, the luma pixel value of the predicted signal is calculated based only on the luma pixel value of the base layer. On the other hand, in the chroma predictor, the chroma pixel value of the predicted signal is calculated based on both the luma and chroma pixel values of the base layer. A residual signal is calculated based on the input UHD EDR signal and the predicted signal. The base layer and residual signal are encoded separately to form an encoded bitstream. A compatible two-layer decoder is also presented.