Subpicture Signaling and Picture Header Layout for Leaner Bitstreams

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Solution Overview

Problem

The increasing demand for high-resolution and high-quality images leads to a significant increase in transmission and storage costs due to the rise in the amount of transmitted information, necessitating improved image compression technologies.

Innovation Solution

An image encoding/decoding method and apparatus that efficiently signals information on subpictures and picture headers, enabling enhanced encoding/decoding efficiency and effective bitstream transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-resolution and high-quality image data is transmitted, then image quality is improved, but transmission cost and storage cost increase

Engineering Contradiction:
Improveimage qualityVSAvoidamount of transmitted information
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The picture is divided into multiple subpictures, and each subpicture can be independently encoded and transmitted. This segmentation allows for selective transmission of important regions while compressing or omitting less important areas, thereby maintaining image quality for critical regions while reducing overall data volume

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different encoding parameters and quality levels are applied to different regions within the picture. Important regions (such as regions containing significant content) are encoded with higher quality, while less important regions use lower quality encoding, optimizing the balance between overall image quality and transmission efficiency

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If picture header information is signaled in slice header, then flexibility in encoding is improved, but device complexity increases

Engineering Contradiction:
Improveencoding flexibilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Picture header information is prepared and organized in advance at the picture level, and then selectively referenced or reused in slice headers. This preliminary organization allows slices to inherit common parameters without retransmitting them, reducing redundancy while maintaining flexibility for slice-specific adjustments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Picture header information is copied and reused across multiple slices within the same picture. Instead of fully signaling the picture header in each slice, essential parameters are copied from the picture-level header, reducing the signaling overhead in individual slice headers while maintaining encoding flexibility

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4093030B1Image encoding/decoding method and device for signaling information related to sub picture and picture header, and method for transmitting bitstream
Publication Date: 2026.04.15 LG ELECTRONICS INC
  • EP4093030B1 patent drawingFigure 1
  • EP4093030B1 patent drawingFigure 2
  • EP4093030B1 patent drawingFigure 3

AI summary

Disclosed herein are an image encoding and decoding method and apparatus for signaling information on a subpicture and picture header, and a method of transmitting a bitstream. The image decoding method according to the present disclosure may include acquiring a first flag specifying whether information on a subpicture is present in a bitstream, acquiring a second flag specifying whether picture header information is present in a slice header, and decoding the bitstream based on the first flag and the second flag. When the first flag specifies that the information on the subpicture is present in the bitstream, the second flag may have a value specifying that the picture header information is not present in the slice header.