Inverse Transform Cropping for Sparse Frequency Coefficient Blocks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Inverse transform processing in image and video coding requires significant computational resources and efficiency, particularly due to the need to calculate non-zero and zero frequency coefficients, leading to resource waste and inefficiency.

Innovation Solution

Determine a non-zero block in the frequency coefficient matrix and perform inverse transform calculations only on this block, using a cropped transform and transposed submatrix, thereby reducing unnecessary calculations on zero coefficients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inverse transform processing is performed on the entire frequency coefficient matrix, then the complete image data can be reconstructed, but the calculation amount increases significantly and processing efficiency decreases

Engineering Contradiction:
Improveimage data reconstruction completenessVSAvoidinverse transform processing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts only the non-zero frequency coefficients from the frequency coefficient matrix and performs inverse transform processing solely on this extracted submatrix. This is achieved by first identifying the positions of non-zero coefficients, then constructing a reduced transform matrix corresponding only to these non-zero elements, thereby eliminating unnecessary calculations on zero coefficients while maintaining complete image data reconstruction capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the frequency coefficient matrix into non-zero blocks and zero regions. By dividing the matrix into meaningful segments based on the positions of non-zero coefficients, the system can process only the relevant segments (non-zero blocks) while ignoring the zero regions, thus reducing overall computational complexity without affecting reconstruction quality

Inventive Principle:
Principle #1Segmentation

2Reliability

If inverse transform processing is performed on all frequency coefficients including zero coefficients, then mathematical completeness is maintained, but computational resources are wasted

Engineering Contradiction:
Improvemathematical completenessVSAvoidcomputational resource consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and processes only the non-zero frequency coefficients, eliminating the need to perform calculations on zero coefficients. This extraction approach maintains mathematical completeness for the relevant data while significantly reducing computational resource consumption, as zero coefficients contribute nothing to the final reconstructed image data

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of performing complete inverse transform on the entire matrix (excessive action), the patent applies partial inverse transform only to the necessary non-zero coefficient regions. This partial action is sufficient to achieve the desired reconstruction without the waste of computing resources on zero coefficients

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS12489922B2Image processing method and apparatus, electronic device, and storage medium
Publication Date: 2025.12.02 SHANGHAI BILIBILI TECH CO LTD
  • US12489922B2 patent drawing
  • US12489922B2 patent drawing
  • US12489922B2 patent drawing

AI summary

The present disclosure provides an image processing method and apparatus, a device, and a medium, and relates to the field of image and video processing technologies. An implementation solution includes: performing frequency domain transform on a target image and obtaining a frequency coefficient matrix of the target image, the frequency coefficient matrix including at least one non-zero frequency coefficient; determining a non-zero block in the frequency coefficient matrix based on a position of the at least one non-zero frequency coefficient; determining a corresponding transform submatrix and a corresponding transposed submatrix of the non-zero block; and determining an inverse transform result of the frequency coefficient matrix based on the transform submatrix, the non-zero block, and the transposed submatrix.