Implicit Illumination Compensation in Video Coding
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Solution Overview
Problem
Existing multi-view video coding technologies face inefficiencies in compression due to illumination and chrominance differences across views from uncalibrated cameras, which are exacerbated by the need for explicit signaling of illumination compensation information, increasing data overhead and reducing prediction efficiency.
Innovation Solution
The method involves implicit illumination and color compensation using causally available neighboring signal statistics, such as offsets from spatially or temporally neighboring blocks, to derive compensation information without explicit signaling, integrating this process with variable block size functionalities in the MPEG-4 AVC standard.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If explicit signaling of illumination compensation information is used, then illumination compensation accuracy is improved, but data overhead increases and compression efficiency deteriorates
Solution Approach 1:
The patent applies self-service by enabling the decoder to autonomously derive illumination compensation information using causally available neighboring signal statistics without requiring explicit signaling from the encoder. The decoder uses offsets from spatially or temporally neighboring blocks to generate compensation parameters, making the system self-sufficient and eliminating the need for additional data transmission.
Solution Approach 2:
The patent uses causally available neighboring signal statistics as an intermediary to transfer illumination compensation information implicitly. Instead of directly signaling compensation parameters, the system uses neighboring block offsets as mediators that the decoder can utilize to reconstruct illumination compensation information, achieving accurate compensation without explicit data transmission.
2Measurement precision
If explicit syntax elements for illumination compensation are signaled, then prediction accuracy is improved, but coding efficiency deteriorates due to additional overhead
Solution Approach 1:
The decoder performs self-service by automatically generating illumination compensation parameters from causally available neighboring signal statistics. This eliminates the need for the encoder to signal explicit syntax elements, thereby maintaining high prediction accuracy while avoiding the bit overhead that would reduce coding efficiency.
Solution Approach 2:
The patent performs preliminary action by having the decoder prepare illumination compensation information using causally available neighboring statistics before the actual decoding process. This advance preparation using existing data eliminates the need for additional signaling, improving both prediction accuracy and coding efficiency.
3Reliability
If illumination compensation information is transmitted explicitly, then compensation effectiveness is improved, but transmission cost increases
Solution Approach 1:
The system achieves self-service by enabling the decoder to generate compensation information autonomously from causally available neighboring signal statistics. This eliminates the need for transmitting compensation data, maintaining compensation effectiveness while reducing data transmission costs to zero for this information.
Solution Approach 2:
The patent uses copying by having the decoder replicate illumination compensation information from causally available neighboring blocks. Instead of transmitting original compensation data, the system copies relevant statistical information from neighboring blocks that the decoder already possesses, achieving effective compensation without additional transmission.
Data Source
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AI summary
There are provided method and apparatus for local illumination and color compensation without explicit signaling. An apparatus includes an encoder (100) for encoding a picture by enabling at least one of color compensation and illumination compensation of at least one color component of a prediction for an image block of the picture without using explicit signaling. The method comprises at least the step of enabling the encoding of a picture described above in the apparatus (325), again without use of explicit signaling. In the description of an specific embodiment, this enabling of the color compensation and the illumination compensation is based on at least one of a group of pixels and a local signal block corresponding to the picture (330). Similar descriptions are provided for a method and apparatus for decoding the signal the encoded signal.