Video Compression Color Space Scalability
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Solution Overview
Problem
Legacy systems based on lower resolution HD content struggle to utilize compressed UHDTV content due to differences in resolution, quantization bit-depth, and color gamut, leading to inefficient use of resources when simulcasting both HD and UHDTV bitstreams.
Innovation Solution
A video coding system that includes a video encoder and decoder with an enhancement layer encoder/decoder to generate and decode UHDTV content using scaled color prediction from a BT.709 image frame, allowing for efficient encoding and decoding of UHDTV content while transmitting only necessary color prediction parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate simulcasting of HD and UHDTV bitstreams is implemented, then legacy systems can decode and utilize HD content, but processing bandwidth and storage resources are inefficiently used
Solution Approach 1:
The patent combines HD and UHDTV encoding into a single unified bitstream by using color space prediction, where the enhancement layer encodes only the differences between color spaces rather than separate full bitstreams. This merging approach maintains legacy system compatibility while significantly reducing processing bandwidth and storage resource consumption.
Solution Approach 2:
The unified bitstream structure allows a single encoded stream to serve multiple functions: legacy systems can extract and decode the base HD layer, while enhanced systems can utilize the full enhancement layer for UHDTV quality. This multi-functionality eliminates the need for separate simulcasting infrastructure.
2Productivity
If color space prediction is used to encode UHDTV content from BT.709 frames, then processing efficiency improves, but complexity of color space transformation increases
Solution Approach 1:
The patent transforms the color space by changing parameters (chroma subsampling ratios, color matrix coefficients, bit-depth) rather than completely reprocessing the image data. This parameter-based approach improves processing efficiency while managing transformation complexity through standardized color space conversion algorithms.
3Manufacturing precision
If enhancement layer encodes color prediction parameters, then UHDTV quality is maintained, but bandwidth consumption increases
Solution Approach 1:
The enhancement layer extracts and encodes only the essential color prediction parameters needed to transform BT.709 color space to UHDTV color space, rather than transmitting complete UHDTV frames. This extraction approach maintains UHDTV image quality while minimizing bandwidth consumption by transmitting only the differential information.
Data Source
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AI summary
An image decoder includes a base layer to decode at least a portion of an encoded video stream into a first image having a first image format. The image decoder can generate a color space prediction by scaling a color space of the first image from the first image format into a color space corresponding to a second image format. The image decoder includes an enhancement layer to decode the encoded video stream to generate a second image in the second image format based, at least in part, on the color space prediction.