Selective DCT/DST Image Coding for Blockwise Compression Efficiency

Solution Overview

Problem

Existing image coding methods, such as H.264/MPEG-4 AVC, face limitations in achieving optimal compression efficiency due to reliance on a single transform method, which can be improved by incorporating both discrete cosine and sine transforms to adaptively select the most efficient transform scheme for each block.

Innovation Solution

An image coding apparatus that employs both discrete cosine and sine transforms to generate transform coefficients, with a scheme determining unit selecting the optimal transform for each block based on distortion and bit rate considerations, enhancing compression efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single transform method (DCT) is used for image coding, then the device complexity is reduced, but the coding efficiency and compression rate are limited

Engineering Contradiction:

Improvetransform method complexityVSAvoidcoding efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent implements dynamic transform selection by determining whether to apply DCT or DST based on block characteristics (e.g., prediction mode, block position). This allows the transform method to adapt dynamically to different image content regions, improving coding efficiency without significantly increasing overall system complexity through conditional logic rather than always using the most complex method

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies different transform methods (DCT or DST) to different blocks or regions of the image based on local characteristics such as prediction mode and block position. This local adaptation allows optimal transform selection for each region, improving overall coding efficiency while maintaining manageable complexity through localized decisions

Inventive Principle:

Principle #3Local quality

2Productivity

If both DCT and DST are implemented for selective use, then the coding efficiency is improved, but the device complexity increases

Engineering Contradiction:

Improvecoding efficiencyVSAvoidtransform method complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic transform selection by determining whether to apply DCT or DST based on block characteristics (e.g., prediction mode, block position). This allows the transform method to adapt dynamically to different image content regions, improving coding efficiency without significantly increasing overall system complexity through conditional logic rather than always using the most complex method

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies different transform methods (DCT or DST) to different blocks or regions of the image based on local characteristics such as prediction mode and block position. This local adaptation allows optimal transform selection for each region, improving overall coding efficiency while maintaining manageable complexity through localized decisions

Inventive Principle:

Principle #3Local quality

3Productivity

If adaptive transform selection is implemented, then the compression rate increases, but the computational complexity increases

Engineering Contradiction:

Improvecompression rateVSAvoidcomputational complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic transform selection by determining whether to apply DCT or DST based on block characteristics (e.g., prediction mode, block position). This allows the transform method to adapt dynamically to different image content regions, improving coding efficiency without significantly increasing overall system complexity through conditional logic rather than always using the most complex method

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies different transform methods (DCT or DST) to different blocks or regions of the image based on local characteristics such as prediction mode and block position. This local adaptation allows optimal transform selection for each region, improving overall coding efficiency while maintaining manageable complexity through localized decisions

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250252609A1Apparatus and method for coding/decoding image selectively using discrete cosine/sine transform

Publication Date: 2025.08.07 DOLBY LABORATORIES LICENSING CORP

AI summary

Disclosed is a data transmission system that transmits data by using a relay. The relay selects a transmission terminal from among a plurality of terminals accessing a base station. A base station transmits base station data to the relay during a first time slot, and the transmission terminal transmits terminal data to the relay. The relay transmits terminal data to the base station during a second time slot, and transmits base station data to the transmission terminal.