Chroma Array Signaling for Block Prediction in Image Decoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing demand for high resolution and high quality images/video, such as 4K and 8K Ultra High Definition, along with the rise of virtual reality and immersive media, necessitates a highly efficient image/video compression technique to reduce transmission and storage costs, particularly in signaling information on chroma format.
Innovation Solution
A method and apparatus for improving image coding efficiency by signaling information on chroma format, predicting a current block based on chroma array type, and determining whether the tree type for deriving the current block is a single tree or dual tree, using a decoding apparatus with an entropy decoder, predictor, and adder, and an encoding apparatus with a predictor, residual processor, and entropy encoder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high resolution and high quality image/video (4K, 8K UHD) are transmitted and stored, then image quality and resolution are improved, but transmission and storage costs are increased
Solution Approach 1:
The patent extracts and processes chroma components separately from luma components. By deriving chroma array types specifically for chroma blocks and applying separate prediction methods, the patent targets only the chroma portion of the image data for specialized compression, reducing overall bitrate while maintaining image quality.
Solution Approach 2:
The patent segments the image processing into separate luma and chroma handling. Different prediction modes (intra prediction, inter prediction, copy prediction) are applied specifically to chroma blocks based on their chroma array type, allowing optimized compression for different color component characteristics.
2Measurement precision
If chroma format information is signaled with high detail, then chroma prediction accuracy is improved, but bitstream overhead is increased
Solution Approach 1:
The patent applies local quality by deriving chroma array types specifically for chroma blocks where needed, rather than uniformly processing all blocks. The chroma format information is signaled and processed locally at the chroma block level, providing prediction accuracy where chroma data exists while avoiding overhead in luma-only regions.
Solution Approach 2:
The patent performs partial action by applying chroma-specific prediction methods only to chroma blocks with non-zero chroma array types. Instead of processing all blocks with full chroma prediction machinery, the patent conditionally applies prediction based on chroma format presence, reducing unnecessary overhead.
3Productivity
If separate prediction methods are applied to luma and chroma blocks, then prediction efficiency is improved, but processing complexity is increased
Solution Approach 1:
The patent achieves universality by using the same set of prediction modes (intra, inter, copy prediction) for both luma and chroma blocks. The prediction framework is multi-functional, handling different color components with the same core algorithms, thereby reducing processing complexity while maintaining prediction efficiency.
Solution Approach 2:
The patent changes parameters conditionally based on block type. The chroma array type parameter determines which prediction methods are applied, allowing the system to adapt processing complexity to the actual data characteristics rather than using fixed complex processing for all blocks.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An image decoding method performed by a decoding device according to the present disclosure comprises the steps of: receiving a bitstream including prediction information for a current block; deriving a chroma array type for the current block on the basis of a separate color plane flag indicating whether three color components are separately coded and a chroma format index indicating a chroma format sampling structure for the current block, which are included in the prediction information for the current block; deriving prediction samples for the current block on the basis of the derived chroma array type; and deriving reconstructed samples for the current block on the basis of the prediction samples.