Image Signal Processor Flicker Correction via Segmented Waveform and Reference Methods

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Solution Overview

Problem

Existing image signal processing methods inadequately remove flicker components from image signals, particularly in environments with changing light source frequencies and frame rates, leading to incomplete correction and reduced accuracy.

Innovation Solution

An image signal processor comprising an integrator, a first flicker corrector that extracts and reduces flicker components based on light source frequency, and a second flicker corrector that generates a reference image without flicker components, using a combination of waveform approximation and level-change detection to dynamically adjust correction methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If waveform approximation method is used to correct flicker, then resistance to level change is improved, but correction accuracy deteriorates

Engineering Contradiction:

Improveresistance to level changeVSAvoidcorrection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The flicker correction process is divided into two distinct stages: first, waveform approximation is applied to provide robustness against level changes; second, reference image-based correction is applied to achieve high correction accuracy. This segmentation allows each method to be optimized for its specific strength while avoiding their respective weaknesses.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent combines two previously separate flicker correction methods (waveform approximation and reference image-based correction) into a unified correction pipeline. By merging these methods sequentially, the system achieves both the level-change resistance of waveform approximation and the high accuracy of reference image correction.

Inventive Principle:

Principle #5Merging (Combining)

2Measurement precision

If reference image method is used to correct flicker, then correction accuracy is improved, but vulnerability to level change worsens

Engineering Contradiction:

Improvecorrection accuracyVSAvoidvulnerability to level change

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

Waveform approximation is applied as a preliminary action before reference image-based correction. This preliminary processing removes the bulk of flicker components and provides level-change robustness, creating a stable foundation for the subsequent high-accuracy reference image correction method.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If single method is used for flicker correction, then device complexity is reduced, but flicker removal completeness deteriorates

Engineering Contradiction:

Improvecorrection method simplicityVSAvoidflicker removal completeness

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The correction system is segmented into two functional blocks: a waveform approximation unit and a reference image correction unit. This segmentation enables comprehensive flicker removal by addressing different aspects of the flicker problem, while keeping each individual unit relatively simple in design.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS9451176B2Image signal processor that reduces a flicker component of an image signal depending on a level change between continuous frames

Publication Date: 2016.09.20 SONY GROUP CORP

AI summary

Provided is an image signal processor, including: an integrator configured to integrate each frame of an image signal; a first flicker corrector configured to extract a flicker component from the integrated value obtained by the integrator, the flicker component depending on a frequency of a light source, and to reduce a flicker component from the integrated value sequentially; and a second flicker corrector configured to generate a reference image without a flicker component based on the correction result of the integrated value corrected by the first flicker corrector, and to correct a flicker of the image signal based on the reference image.