Patent ID: 9699484
Date: 2017-07-04
CPC Classifications: H04N

Claim:
1. A method for decoding a layered stream with a decoder comprising a processor, the method comprising: receiving a coded bitstream, the coded bitstream comprising a coded enhancement layer (EL) stream with a first spatial resolution and a first dynamic range and a coded base layer (BL) stream with a second spatial resolution and second dynamic range, wherein the first dynamic range is higher than the second dynamic range; decoding the coded BL stream using a BL decoder to generate a first decoded BL signal; in response to the decoded BL signal, generating a predicted signal with the first dynamic range, wherein luma pixel values of the predicted signal are predicted based only on luma pixel values of the decoded BL signal, and chroma pixel values of at least one chroma component of the predicted signal are predicted based on both the luma and chroma pixel values of the decoded BL signal; decoding the coded EL stream using an EL decoder to generate a decoded residual signal; and generating an output signal with the first resolution and the first dynamic range in response to the decoded residual signal and the predicted signal; wherein the first spatial resolution is higher than the second spatial resolution, and generating the output signal further comprises: up-sampling the predicted signal to generate an up-sampled predicted signal with the first spatial resolution; and generating the output signal with the first resolution and the first dynamic range in response to the decoded residual signal and the up-sampled predicted signal; wherein generating the up-sampled predicted signal further comprises: receiving from an encoder luma thresholds to divide a luminance range into luminance sub-ranges; receiving from the encoder up-scale filter information for each of said luminance sub-ranges; for one or more pixels in the predicted signal, applying the luma thresholds and a selection criterion to determine for one or more corresponding pixels in the decoded BL signal a luminance sub-range among the luminance sub-ranges; and applying to said one or more pixels in the predicted signal the up-scaling filter corresponding to said luminance sub-range to generate corresponding pixel values for the up-sampled predicted signal.