Illumination Compensation for Block Prediction in Video Coding
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Solution Overview
Problem
The increasing demand for high-resolution and high-quality images leads to a significant increase in video data, necessitating an efficient video compression technology that can effectively manage the increased data volume, particularly in varying device and network environments.
Innovation Solution
A block prediction method that compensates for illumination differences between the current and reference blocks, using illumination compensation to enhance prediction efficiency and reduce the data required for residual signals, thereby improving compression and coding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-resolution and high-quality images are used, then image quality is improved, but the amount of data increases
Solution Approach 1:
The patent extracts and removes the illumination component from the image block by calculating illumination parameters (a, b) and applying illumination compensation to generate a compensated block. This separates the illumination variation from the actual image content, allowing the residual to capture only the essential image information, thus reducing the amount of data needed to represent high-quality images.
Solution Approach 2:
The patent changes the parameter representation by introducing illumination parameters (a, b) that describe the illumination transformation. By modeling illumination as a linear transformation parameter and compensating for it, the patent reduces the residual energy and consequently the data required to encode high-quality images.
2Productivity
If block prediction efficiency is increased through illumination compensation, then compression efficiency is improved, but the complexity of the coding process increases
Solution Approach 1:
The patent performs preliminary illumination compensation before the main prediction and coding processes. By pre-calculating the illumination parameters (a, b) from neighboring blocks and applying the compensation in advance, the patent simplifies the subsequent coding process while improving compression efficiency, as the residual block already has reduced energy requiring less encoding complexity.
Solution Approach 2:
The patent uses the reconstructed neighboring blocks themselves to derive the illumination parameters, making the system self-service. The neighboring blocks that are already available in the reconstruction buffer are utilized to compute the illumination model, eliminating the need for additional external information or complex preprocessing, thus balancing complexity and efficiency.
Data Source
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Figure 3(a)~3(b)
AI summary
A block prediction method for decoding a picture, according to the present invention, comprises the steps of: deriving a reference block from a reference picture to predict a current block in a current picture; determining a reference illumination compensation (IC) parameter; generating an illumination-compensated reference block by applying reference IC to the reference block on the basis of the reference IC parameter; and generating a predicted sample of the current block on the basis of the illumination-compensated reference block. According to the present invention, an illumination difference between the current block of the current picture and the reference block of the reference picture can be compensated for, block prediction efficiency can be increased, and a data amount of a residual signal to be transmitted from an encoder to a decoder is reduced. Therefore, compression and coding efficiency can be increased.