Bit-Depth Scalable Image Encoding Using Segmented Layers
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Solution Overview
Problem
Conventional image coding techniques result in an increase in data amount when processing pictures with a bit-depth higher than supported by 8-bit video processors, leading to higher recording capacity and bandwidth requirements.
Innovation Solution
An image coding apparatus that down-converts a target picture to a base layer with a predetermined bit-depth, generates an enhancement layer by shifting the bit-depth of the reconstructed picture, and codes both layers separately to reduce data transmission while maintaining image quality, using a subtractor to adjust the bit-depth and determine optimal shift values based on picture characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple 8-bit video processors are used to process a 10-bit picture, then the image processing capability is achieved, but the data amount increases significantly
Solution Approach 1:
The patent segments the 10-bit picture processing into two separate 8-bit processing stages: base layer processing and enhancement layer processing. The base layer contains the most significant bits (MSBs) processed by an 8-bit video processor, while the enhancement layer contains the least significant bits (LSBs) processed by another 8-bit video processor. This segmentation allows existing 8-bit processors to handle high-bit-depth content without requiring a single complex 10-bit processor, thereby avoiding the exponential data increase that would occur with naive processing approaches.
Solution Approach 2:
The patent changes the bit-depth parameter during processing by separating the 10-bit picture into two 8-bit layers with different bit allocations. The base layer uses 8 bits per pixel for the MSBs, and the enhancement layer uses 8 bits per pixel for the LSBs. This parameter transformation allows standard 8-bit video processors to process high-bit-depth content efficiently, reducing the overall data amount compared to processing the entire 10-bit picture as a single unit.
2Manufacturing precision
If the bit-depth is increased from 8 bits to 10 bits, then the number of reproducible colors increases 64 times, but the recording capacity and bandwidth requirements increase
Solution Approach 1:
The patent segments the color information into two separate 8-bit layers (base layer and enhancement layer) that can be processed and stored independently using standard 8-bit video processors. Each layer contains 8 bits per pixel, but together they reconstruct the 10-bit color information. This segmentation maintains the 64-times color reproduction capability of 10-bit depth while avoiding the need to store and transmit the full 10-bit data continuously, as the enhancement layer can be selectively applied based on display capabilities.
Solution Approach 2:
The patent dynamically adjusts the effective bit-depth parameter based on the processing stage and display capabilities. The base layer is processed at 8 bits, and the enhancement layer adds additional precision when needed. This parameter flexibility allows the system to achieve 10-bit color reproduction precision only where necessary, reducing overall recording capacity requirements compared to uniformly storing all content at full 10-bit depth.
3Manufacturing precision
If conventional coding methods are used for high bit-depth pictures, then the image quality is maintained, but the bandwidth requirement increases
Solution Approach 1:
The patent segments the video stream into base layer and enhancement layer, where the base layer can be decoded independently to provide acceptable image quality, and the enhancement layer provides additional quality improvement when bandwidth is available and the display device supports it. This segmentation enables progressive delivery where the base layer consumes minimal bandwidth for basic quality, and the enhancement layer consumes additional bandwidth only when needed to maintain high image quality for capable devices.
Solution Approach 2:
The patent changes the effective bit-depth parameter based on transmission conditions and receiver capabilities. The base layer is transmitted at 8 bits with lower bandwidth requirements, while the enhancement layer transmits the remaining bits to achieve full 10-bit quality. This parameter adaptation allows the system to maintain image quality at 10 bits only when the full bandwidth is available, reducing bandwidth requirements for basic quality service while preserving the option for high-quality transmission.
Data Source
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AI summary
To reduce the amount of data involved in coding a picture having a bit-depth higher than a bit-depth supported by an encoder, an image coding apparatus (100A) according to an aspect of the present invention includes: a down-converter (102A) which generates a base layer picture by down-converting a target picture to reduce the bit-depth of the target picture by a first value; a first encoder (111A) which codes the base layer picture, and generates a reconstructed picture by decoding the coded base layer picture; a subtractor (103A) which performs shift amount adjustment on the reconstructed picture to increase the bit-depth of the reconstructed picture by a second value, and generates, based on the reconstructed picture on which the adjustment has been performed and the target picture, an enhancement layer picture for enhancing the quality of the base layer picture; a second encoder (112A) which codes the enhancement layer picture; and an output unit (115) which outputs the coded base layer picture and the coded enhancement layer picture.