Encoder Subpicture Region Definition Using CTU Grids

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Solution Overview

Problem

Current video coding technologies face challenges in efficiently processing and identifying subpicture regions within videos, as existing methods struggle to accurately define and encode subpicture information using coding tree units (CTUs) across multiple pictures.

Innovation Solution

An encoder and decoder system that encodes and decodes subpicture information by representing subpicture regions using a grid of coding tree units (CTUs), allowing flexible definition of subpicture shape, location, and size, and reduces code amount by using delta values for reference CTU indices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If subpicture information is encoded using conventional methods without CTU-based representation, then the encoding process is simpler, but the precision in defining subpicture regions across multiple pictures deteriorates

Engineering Contradiction:

Improvesubpicture region definition precisionVSAvoidencoding system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The picture is divided into multiple subpictures, and each subpicture is further divided into CTUs (Coding Tree Units). This segmentation allows precise definition of subpicture regions by specifying CTU indices for top-left and bottom-right positions, enabling accurate region identification while maintaining manageable encoding complexity through hierarchical structure.

Inventive Principle:

Principle #1Segmentation

2Loss of substance

If delta values are not used for reference CTU indices, then the encoding process is more straightforward, but the code amount increases

Engineering Contradiction:

Improvecode amountVSAvoidencoding complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

Instead of directly encoding absolute CTU indices, the system encodes delta values (differences) between the current CTU index and reference CTU indices. This parameter transformation reduces the number of bits required for encoding while maintaining the ability to accurately represent any CTU position through simple addition of the delta value to the reference index.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If subpicture information is encoded with full detail for each picture, then the accuracy is maintained, but the productivity decreases

Engineering Contradiction:

Improvevideo coding efficiencyVSAvoidsubpicture information accuracy

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The system performs preliminary encoding of subpicture information by defining the region using only top-left and bottom-right CTU indices. This preliminary definition is sufficient to identify the subpicture region across multiple pictures without requiring detailed encoding of every pixel or block, thereby maintaining accuracy while significantly improving coding efficiency.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20220264155A1Encoder, decoder, encoding method, decoding method, and medium

Publication Date: 2022.08.18 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

AI summary

An encoder includes circuitry and memory coupled to the circuitry. In operation, the circuitry encodes subpicture information in which a width and a height of a subpicture which is a rectangular region in a picture are represented in a unit of a coding tree unit (CTU).