Adaptive Transform Base Generation for Video Encoding
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Solution Overview
Problem
Current video encoding technologies face inefficiencies in intra prediction encoding due to the inability to adaptively generate optimal transform bases for varying image characteristics, leading to suboptimal energy concentration and compression efficiency.
Innovation Solution
A video encoding apparatus and method that adaptively generates Karhunen-Loeve Transform (KLT)-based transform bases based on autocorrelation matrices calculated from prediction errors, allowing for efficient transform-encoding of intra prediction errors according to local characteristic changes and intra prediction modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fixed transform base is used for intra prediction encoding, then the encoding process is simple and fast, but the energy concentration effect is insufficient and compression efficiency is suboptimal
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed transform base to an adaptive transform base that changes according to image characteristics. The transform base is dynamically generated based on the autocorrelation matrix of prediction errors, allowing the encoding system to adapt to different image contents and achieve optimal energy concentration for each specific encoding situation.
Solution Approach 2:
The patent changes the parameter of the transform base according to image characteristics. By calculating the autocorrelation matrix from prediction errors and deriving transform bases from this matrix, the system adjusts the transform parameters adaptively. This parameter change enables the system to optimize energy concentration and compression efficiency for different image types without requiring additional bits to signal the transform base.
2Productivity
If adaptive transform bases are generated according to image characteristics, then energy concentration and compression efficiency are improved, but the computational complexity and processing time increase
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing transform bases in a lookup table during an initialization phase. During actual encoding, the system only needs to retrieve the appropriate transform base from the table based on image characteristics, rather than computing it in real-time. This preliminary preparation significantly reduces encoding processing time while maintaining the benefits of adaptive transform bases.
3Adaptability or versatility
If additional information is added to signal transform bases, then adaptability to different image characteristics is improved, but the bitstream complexity and encoding overhead increase
Solution Approach 1:
The patent applies self-service by enabling the encoding system to automatically determine and generate transform bases based on the inherent characteristics of the image data itself. The system uses the autocorrelation matrix of prediction errors to derive transform bases, eliminating the need for external signaling. This self-determining mechanism provides adaptability without requiring additional bits in the bitstream, as the transform base is implicitly derived from the image content.
Data Source
AI summary
A video encoding apparatus includes an intra prediction error collector; a transform base generator; an intra predictor; and a transform encoder, the intra prediction error collector collecting prediction errors of blocks having an equal intra prediction mode from macroblocks in a regular unit, which are encoded prior to a current macroblock, the transform base generator generating transform bases for respective intra prediction modes based on the prediction errors collected by the intra prediction error collector. Accordingly, the intra prediction encoding performance can be significantly improved with adding no addition information by adaptively generating a transform base according to an image characteristic change and transform-encoding an intra prediction error. As a result, the compression efficiency of a video compression apparatus or the picture quality of a reconstructed image can be greatly improved.