Image Encoding Motion Vector Candidate Selection

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Solution Overview

Problem

Conventional image encoding and decoding methods face complexity in calculating motion information for neighbor blocks, leading to inefficiencies in inter-prediction and intra-prediction processes, necessitating improved performance and efficiency.

Innovation Solution

An image encoding and decoding method that selects a motion vector candidate by determining the usability of neighbor blocks based on flags and prediction modes, and uses motion vector differences to derive motion information, optimizing prediction block generation and encoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temporal prediction mode is used between pictures for motion information prediction, then prediction accuracy is improved, but calculation complexity increases

Engineering Contradiction:
Improveprediction accuracyVSAvoidcalculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent dynamically adjusts the prediction approach by determining whether to use temporal prediction or intra-picture prediction based on block characteristics and motion activity. This dynamic selection optimizes the balance between prediction accuracy and computational complexity by adapting the prediction method to the specific content being encoded.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the prediction parameters by using different reference blocks (spatial vs. temporal) and different prediction modes based on the characteristics of the current block. This allows the system to switch between high-accuracy temporal prediction and lower-complexity spatial prediction as needed.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If intra-prediction is made complicated to improve encoding performance, then image encoding performance is improved, but device complexity increases

Engineering Contradiction:
Improveimage encoding performanceVSAvoidintra-prediction complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the prediction process into distinct modes (temporal prediction, spatial prediction, and their combinations) that can be independently selected and optimized. This segmentation allows complex prediction functionality to be achieved through modular, selectable components rather than a monolithic complex algorithm.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by selectively applying complex prediction methods only to blocks that benefit from them, while using simpler methods for other blocks. This is achieved through conditions that determine when to use temporal vs. spatial prediction based on motion characteristics and block content.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If motion vector candidate selection is simplified, then device complexity is reduced, but prediction accuracy deteriorates

Engineering Contradiction:
Improvecandidate selection complexityVSAvoidmotion information accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary actions by pre-identifying and organizing potential motion vector candidates from both spatial and temporal references before the actual prediction process. This preliminary organization allows for efficient selection of the best candidate without requiring complex real-time analysis during encoding.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses motion vector differences as an intermediary mechanism to bridge between simple candidate selection and accurate motion compensation. By encoding and transmitting only the difference between predicted and actual motion vectors, the system achieves high accuracy without requiring complex candidate evaluation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4221202A1Image encoding and decoding method and image decoding device
Publication Date: 2023.08.02 DOLBY LABORATORIES LICENSING CORP
  • EP4221202A1 patent drawingFigure 1
  • EP4221202A1 patent drawingFigure 2
  • EP4221202A1 patent drawingFigure 3

AI summary

Disclosed are an image encoding and decoding method and an image decoding device for selecting a prediction candidate from reference blocks of a reference picture, which includes a current picture, and using the selected prediction candidate so as to derive motion information on a current block during image encoding and decoding. The image encoding and decoding method includes the steps of: configuring a spatial motion vector candidate; determining whether the reference picture of the current block is present within the current picture; and adding a spatial motion vector candidate in other block of the current picture encoded before the current block, when the reference picture of the current block is present within the current picture.