Intra Prediction Using DIMD Modes to Cut Bitstream Overhead

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Solution Overview

Problem

The increasing demand for high-resolution, high-quality video and immersive media formats like VR and AR necessitates more efficient image compression techniques to reduce transmission and storage costs while maintaining or improving prediction accuracy.

Innovation Solution

The method involves deriving intra prediction modes using Decoder side Intra Mode Derivation (DIMD) information from a bitstream, determining if DIMD is applied to a current block, and generating prediction samples based on these modes, thereby reducing overhead and improving coding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If intra prediction mode is signaled through the bitstream, then prediction accuracy can be maintained, but signaling overhead increases and coding efficiency decreases

Engineering Contradiction:

Improvesignaling overheadVSAvoidprediction accuracy

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The decoder derives the intra prediction mode autonomously using DIMD (Decoder-side Intra Mode Derivation) based on already decoded pixels and gradient calculations, eliminating the need for the encoder to signal the prediction mode explicitly. This self-service mechanism reduces signaling overhead while maintaining prediction accuracy through mathematical derivation from local image characteristics.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The prediction mode is pre-derived at the decoder side using gradient calculations and pixel analysis before actual decoding occurs. By performing preliminary action through gradient-based mode selection and weighted average calculations, the system eliminates the need for subsequent mode signaling in the bitstream.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If high resolution video is transmitted, then video quality improves, but transmission and storage costs increase

Engineering Contradiction:

Improvevideo qualityVSAvoidtransmission and storage costs

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

The decoder autonomously determines intra prediction modes using DIMD without requiring additional mode information in the bitstream. This reduces the amount of data that needs to be transmitted and stored, thereby lowering transmission and storage costs while maintaining high video quality through accurate gradient-based prediction.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system changes the parameter representation from explicit mode signaling to implicit gradient-based derivation. By using gradient calculations and pixel intensity relationships instead of direct mode indexing, the system achieves more efficient compression with reduced bitstream overhead for high-resolution video.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20260039863A1Method and device for intra prediction based on plurality of DIMD modes

Publication Date: 2026.02.05 LG ELECTRONICS INC

AI summary

According to one embodiment of the present specification, provided is an image decoding method performed by a decoding device. The method comprises the steps of: acquiring, from a bitstream, image information comprising information related to decoder-side intra mode derivation (DIMD); determining, on the basis of the information related to DIMD, whether DIMD is applied to a current block; deriving DIMD modes for the current block on the basis that DIMD is applied to the current block; and generating a prediction sample for the current block on the basis of the DIMD modes.