Image Coding Offset Adjustment for Region Boundary Artifacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image coding methods, such as those in the HEVC standard, suffer from artifacts at region boundaries due to differing pixel classification methods used for calculating offset values, leading to decreased image quality.
Innovation Solution
An image coding method that codes images on a per-region basis, calculating and comparing offset information between current and neighboring regions, adjusting offset values accordingly to minimize artifacts at boundaries, and storing these adjustments for subsequent coding processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If offset processing is performed independently for each region using different pixel classification methods, then coding flexibility and adaptability to local characteristics is improved, but artifacts occur at region boundaries and image quality deteriorates
Solution Approach 1:
The patent merges offset processing across region boundaries by determining whether neighboring regions use the same pixel classification method. When methods differ, the patent combines offset values from both regions and applies the combined offset to boundary pixels, ensuring continuous offset application across regions and eliminating boundary artifacts while preserving local adaptability
Solution Approach 2:
The patent introduces an intermediary mechanism at region boundaries where offset values from adjacent regions are combined through addition. This intermediary approach allows seamless transition of offset application across boundaries, mediating between different pixel classification methods and preventing visible artifacts
2Measurement precision
If offset values are applied to reduce coding degradation in each region, then reconstruction accuracy is improved, but inconsistency in offset application across regions causes boundary artifacts
Solution Approach 1:
The patent applies local quality by allowing different pixel classification methods in different regions while ensuring consistent boundary treatment. Each region maintains its local characteristics through appropriate classification methods, while boundary pixels receive combined offsets that ensure continuity and consistency across region transitions
3Productivity
If separate offset processing is performed for each region, then processing efficiency is improved, but image quality at boundaries deteriorates due to artifacts
Solution Approach 1:
The patent applies partial action by performing combined offset processing only at boundary pixels where region transitions occur, while maintaining efficient separate processing in interior regions. This selective approach minimizes additional computational overhead while effectively eliminating boundary artifacts
Data Source
AI summary
An image coding method codes an image on a per-region basis. The method includes calculating offset information to be used for applying offset to the current region; determining whether or not the offset information is the same between the current region and a neighboring region of the current region; applying offset using the offset information and a result obtained in the determining, by adding an offset value to a reconstructed signal obtained by coding a pixel signal of the current region and decoding the coded pixel signal; coding the offset information; and storing, into a memory, an offset signal obtained by applying the offset, so that the offset signal is used for coding of a subsequent region.