Virtual Boundary Signaling for Reduced Blur in Video Coding
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Solution Overview
Problem
The use of in-loop filters in video encoding/decoding leads to blurring at boundaries, deteriorating picture quality, and existing video compression techniques fail to effectively address this issue.
Innovation Solution
A video encoding/decoding method and apparatus that utilizes virtual boundaries with signaling mechanisms to reduce blurring, including information on whether filtering is performed, the number and position of virtual boundaries, and reconstructs pictures based on this information, using sequence parameter sets and picture headers for signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If in-loop filter is used to reduce blocking artifact, then blocking artifact and ringing distortion are reduced, but blurring is caused at boundaries resulting in deterioration of picture quality
Solution Approach 1:
The patent divides the image into multiple blocks and introduces virtual boundaries between them. By segmenting the image structure and marking virtual boundaries, the system can apply filtering operations selectively at these boundary regions rather than uniformly across the entire image, thereby reducing blurring while maintaining blocking artifact reduction benefits
Solution Approach 2:
The patent applies different filtering strategies to different regions of the image based on their proximity to virtual boundaries. Regions near virtual boundaries receive enhanced filtering to reduce blocking artifacts, while regions away from boundaries maintain sharper characteristics. This local differentiation of filtering quality resolves the contradiction between reducing blocking artifacts and preventing boundary blurring
2Productivity
If video is divided into different regions for block-based prediction, then compression efficiency is improved, but blurring phenomenon is caused at boundaries
Solution Approach 1:
The patent maintains block-based segmentation for compression efficiency but enhances it by introducing virtual boundaries that extend beyond the actual block boundaries. These virtual boundaries create a buffer zone that allows the system to apply boundary-aware filtering, thereby preserving compression efficiency while reducing the blurring effect at region boundaries
Solution Approach 2:
The virtual boundaries act as an intermediary element between the block-based prediction structure and the filtering operation. They mediate the interaction by providing additional spatial information that guides the filtering process, allowing the system to maintain the benefits of block-based compression while avoiding the harmful blurring effect
Data Source
AI summary
Disclosed herein are a video encoding/decoding method and apparatus. The video decoding method according to the present invention includes: obtaining information on whether filtering is performed on a virtual boundary for a current picture from a bitstream; decoding information on the number of virtual boundaries based on the information on whether filtering is performed on a virtual boundary; decoding information on a position of a virtual boundary based on the information on the number of virtual boundaries; and reconstructing the current picture based on the information on the position of the virtual boundary.