Dead Pixel Detection Using Frequency and Pattern Analysis

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Solution Overview

Problem

Existing methods for detecting and compensating dead pixels in image sensors often require excessive hardware resources and can incorrectly identify crowded or high-contrast images as dead pixels, leading to image distortion and deterioration.

Innovation Solution

An apparatus that includes a pixel value storage unit, a dead pixel processing unit, a frequency detection unit, a pattern detection unit, and a selection unit to accurately detect dead pixels by comparing reference pixel values with neighboring pixel values, generating flags based on thresholds, and selecting the appropriate pixel values for compensation, thereby reducing unnecessary compensation and distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional dead pixel detection methods are used, then dead pixels can be detected and compensated, but hardware resources are excessively consumed

Engineering Contradiction:
Improvedead pixel detection accuracyVSAvoidhardware resources
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The dead pixel detection process is divided into multiple stages: initial dead pixel detection, frequency domain analysis, and pattern recognition. Each stage processes only suspicious pixels identified in previous stages, rather than all pixels, thereby reducing overall computational load and hardware resource requirements while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different detection strategies are applied to different regions and types of pixels based on their characteristics. The system applies frequency domain analysis specifically to pixels with extreme values, and pattern recognition to clustered suspicious pixels, rather than using a uniform complex algorithm for all pixels, thus optimizing hardware resource utilization.

Inventive Principle:
Principle #3Local quality

2Reliability

If conventional dead pixel detection methods are used, then dead pixels can be detected, but crowded or high-contrast images are erroneously identified as dead pixels causing image distortion

Engineering Contradiction:
Improvedead pixel detection accuracyVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system uses frequency domain analysis to examine the spatial distribution patterns of pixel values. By analyzing the frequency characteristics of pixel intensity variations, the system can distinguish between true dead pixels (which appear as isolated extreme values) and legitimate high-contrast image features (which exhibit specific frequency patterns), thereby reducing false positives and preventing image distortion.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The detection thresholds and criteria are dynamically adjusted based on the local image characteristics and statistical properties of neighboring pixels. Rather than using fixed thresholds, the system adapts its detection parameters according to the specific image content, allowing it to differentiate between dead pixels and legitimate high-contrast or crowded regions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS7676084B2Apparatus for processing dead pixel
Publication Date: 2010.03.09 MILA CO LTD
  • US7676084B2 patent drawing
  • US7676084B2 patent drawing
  • US7676084B2 patent drawing

AI summary

The present invention is related to a method and an apparatus for processing a dead pixel, more specifically to a method and an apparatus thereof for detecting and compensating a dead pixel that can maintain a good image quality by reducing image distortion and deterioration. With the present invention, the distortion of an image, caused by erroneously classifying a normal pixel of an inputted image as a dead pixel, is significantly reduced, thereby improving the quality of a processed image. Moreover, based on the characteristics of the inputted image, the algorithm and accuracy of detecting a dead pixel can be adjusted.