Encoder Flicker Reduction via Frame-Adaptive Quantization

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Solution Overview

Problem

Flicker in image frames, particularly in background regions, is not effectively addressed by existing encoders, which can lead to objectionable visual disturbances, especially when the image information diverges significantly between successive frames.

Innovation Solution

An encoder system that adapts quantization coefficients using information from both the current and previous frames, employing a transformer to generate frequency domain coefficients, a quantizer to adjust these coefficients, and a coefficient calculator to minimize the absolute difference between inverse-quantized and frequency domain coefficients, thereby reducing flicker.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If quantization coefficients are adjusted using only current frame information, then encoding efficiency is improved, but flicker reduction is insufficient

Engineering Contradiction:

Improveencoding efficiencyVSAvoidflicker reduction

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The encoder performs preliminary action by calculating adjusting coefficients based on both current and previous frame information before final quantization. The coefficient calculator computes adjusting coefficients using motion compensation and previous frame data, then applies these coefficients to reduce flicker in the quantization process, ensuring stable visual output before encoding completion.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by utilizing previous frame information to adjust current frame quantization coefficients. The encoder feeds back motion vector data and previous frame coefficient information to the coefficient calculator, which then modifies adjusting coefficients to compensate for flicker, creating a closed-loop system that improves both encoding efficiency and visual stability.

Inventive Principle:

Principle #23Feedback

2Reliability

If adjusting coefficients are calculated using both current and previous frames, then flicker reduction is improved, but device complexity increases

Engineering Contradiction:

Improveflicker reductionVSAvoidencoder complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The encoder applies local quality by calculating adjusting coefficients for each block individually based on its specific motion characteristics and previous frame data. Rather than applying a global adjustment, the system computes block-specific coefficients using motion compensation, allowing precise flicker reduction in each region while maintaining overall encoder efficiency and avoiding unnecessary complexity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system changes parameters dynamically by adjusting quantization coefficients based on motion vector magnitude and direction. The coefficient calculator modifies adjusting coefficients according to motion intensity and frame differences, adapting the quantization process to local motion characteristics without requiring complex structural changes to the encoder architecture.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If motion compensation is applied for adjusting coefficients, then flicker reduction in moving regions is improved, but processing time increases

Engineering Contradiction:

Improveflicker reduction in moving regionsVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The encoder applies partial action by performing motion compensation and adjusting coefficient calculation only for blocks where motion is detected. The system evaluates motion vector magnitude and applies flicker reduction processing selectively to moving regions rather than processing the entire frame, reducing overall processing time while maintaining effective flicker reduction in areas where it is needed.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS10097830B2Encoding device with flicker reduction

Publication Date: 2018.10.09 SAMSUNG ELECTRONICS CO LTD

AI summary

In an application processor having an encoder configured to reduce flicker occurring in a display, the encoder includes a transformer configured to generate first frequency domain coefficients for individual block values of a current frame, a quantizer configured to quantize the first frequency domain coefficients to generate quantized coefficients, and a coefficient calculator configured to generate first adjusting coefficients for reducing the flicker, where the quantizer is configured to adjust the quantization coefficients based on the first adjusting coefficients and output adjusted quantization coefficients.