Enhancing a chroma-subsampled video stream

A system comprising:

• a network;
• a sender device communicatively coupled to the network;
• and
• a receiver device communicatively coupled to the network;
• wherein the sender device is a computing device configured to send digital video in high-quality compressed form over the network to the receiver device by:
• performing chroma subsampling on an original video stream to yield an altered video stream whose chroma resolution is lower than its luma resolution;
• applying video compression to the altered video stream to yield a compressed base layer (BL) stream;
• creating an enhancement layer (EL) stream based on differences between the original video stream and a decompressed version of the BL stream, the EL stream including additional chroma information, which, when combined with the BL stream, encodes a video stream that has higher chroma fidelity to that of the original video stream than does the BL stream alone, wherein creating the EL stream includes creating a set of mappings that transforms chroma values of particular pixels of the decompressed version of the BL stream into enhanced chroma values that have higher chroma fidelity to that of the original video stream than does the BL stream alone;
• and
• sending both the BL stream and the EL stream to the receiver device across the network;
• and
• wherein the receiver device is a computing device configured to generate and display a version of the original video stream by combining the BL stream with the additional chroma information of the EL stream.

A computer program product comprising a non-transitory computer-readable storage medium storing a set of instructions, which, when executed by a computing device, causes the computing device to generate and display an enhanced video by:

• receiving, from a sender device across a computer network, a base-layer (BL) video stream encoded according to a low-complexity profile of a video codec using chroma subsampling;
• receiving, from the sender device across the computer network, an enhancement layer (EL) stream which includes additional chroma information including a set of mappings that transforms chroma values of particular pixels of a decompressed version of the BL stream into enhanced chroma values that have higher chroma fidelity to that of the original video stream than does the BL stream alone;
• decoding the BL video stream to yield a decoded BL stream;
• applying the additional chroma information received within the EL stream to the decoded BL stream to yield an enhanced output video stream that has higher chroma fidelity to that of an original video stream of the sender device than does the BL stream alone;
• and
• displaying the enhanced output video stream on a display screen.