RGB Prediction Coding Using a Single Mode Across Color Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image and video encoding methods for RGB images, which convert images to YCbCr format, suffer from loss of image quality due to different compression methods for Y, Cb, and Cr components, leading to inefficient encoding and potential color distortion.
Innovation Solution
A method using a single coding mode for all color components, applying identical prediction directions and motion vectors to generate spatial and temporal prediction images, selecting an encoding mode based on bit quantity and distortion calculations to enhance encoding efficiency without converting RGB images to YCbCr format.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If different compression methods are used for Y, Cb, and Cr components in YCbCr format, then compression efficiency is enhanced, but image quality is degraded due to color distortion
Solution Approach 1:
The patent merges the treatment of all color components (R, G, B) by applying the same prediction and compression methods uniformly across all components in the RGB domain, eliminating the separate processing of different color components that causes color distortion while maintaining efficient compression through unified residual transformation and quantization
Solution Approach 2:
The patent changes the color space parameter from YCbCr to RGB, enabling direct processing of RGB images without conversion. This parameter change allows uniform application of prediction and compression methods to all color components, preserving color accuracy while achieving compression efficiency through the residual transformation process
2Productivity
If RGB images are converted to YCbCr format for encoding, then compression efficiency is improved, but color distortion occurs leading to quality loss
Solution Approach 1:
Instead of converting RGB to YCbCr and then compressing, the patent inverts the approach by keeping images in the original RGB format throughout the encoding process and applying compression methods directly to RGB components, thereby preserving color information while achieving compression through unified residual transformation
3Productivity
If spatial prediction is performed using different methods for Y and CbCr components, then encoding efficiency is enhanced, but device complexity increases
Solution Approach 1:
The patent applies a universal prediction and encoding approach that works for all color components (R, G, B) simultaneously. The same prediction modes, residual transformation, and quantization processes are used for all components, eliminating the need for separate processing paths and reducing encoding complexity while maintaining efficiency
Data Source
AI summary
A prediction image generation method and apparatus using a single coding mode for all color components and image and video encoding and decoding methods and apparatuses using the same are provided. The prediction image generation apparatus includes: a spatial prediction image generation unit applying an identical prediction direction for each image component in an original image composed of at least two image components, and obtaining a spatial prediction image from a pixel spatially close to a pixel block of a predetermined size of a current frame; a temporal prediction image generation unit applying an identical block size, motion vector, and motion interpolation method for each image component in an original image composed of at least two image components, and obtaining a temporal prediction image by estimating motion in units of blocks of a predetermined size between a previous frame and a current frame of each of the image components; an encoding mode selection unit selecting an encoding mode by using the spatial prediction image and the temporal prediction image; and a single mode prediction image generation unit generating a prediction image by identically applying the encoding mode selected in the encoding mode selection unit to each component. By increasing the redundancy of information between prediction error signals of color components, the encoding efficiency can be enhanced in the method and apparatus.