Image Sensor Noise Correction via Segmented Pixel Processing

Solution Overview

Problem

Image sensors often suffer from defective pixels and low saturation pixels due to manufacturing variations and degradation, leading to inconsistent pixel values, which existing techniques struggle to accurately correct, especially in uniform high-luminance imaging scenarios.

Innovation Solution

An image processing apparatus and method that processes noise by obtaining image data and saturation levels from each pixel, using a noise processing unit to differentiate and correct defective pixels and low saturation pixels, employing techniques such as variance calculation and interpolation to achieve consistent pixel values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional defective pixel correction techniques are used, then defective pixel noise can be reduced, but low saturation pixels cause false detection and correction errors

Engineering Contradiction:

Improvedefective pixel correction accuracyVSAvoidpixel value uniformity

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent segments the correction process into two distinct parts: defective pixel correction and low saturation pixel correction. By separating these corrections and applying them in a specific sequence (defective pixel correction first, then low saturation pixel correction), the system avoids false detection of low saturation pixels as defective pixels, thereby improving both correction accuracy and pixel value uniformity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies defective pixel correction as a preliminary action before low saturation pixel correction. This preliminary correction establishes a baseline that prevents subsequent low saturation pixel correction from mistakenly identifying and correcting already-corrected defective pixels, thus improving measurement precision

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If saturation-based correction is applied to all pixels, then low saturation pixel values can be corrected, but defective pixels cause correction errors

Engineering Contradiction:

Improvepixel value uniformityVSAvoidcorrection accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent segments the correction process into two distinct parts: defective pixel correction and low saturation pixel correction. By separating these corrections and applying them in a specific sequence (defective pixel correction first, then low saturation pixel correction), the system avoids false detection of low saturation pixels as defective pixels, thereby improving both correction accuracy and pixel value uniformity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies defective pixel correction as a preliminary action before low saturation pixel correction. This preliminary correction establishes a baseline that prevents subsequent low saturation pixel correction from mistakenly identifying and correcting already-corrected defective pixels, thus improving measurement precision

Inventive Principle:

Principle #10Preliminary action

3Reliability

If variance-based defective pixel detection is used, then defective pixels can be identified, but low saturation pixels are falsely detected as defective

Engineering Contradiction:

Improvedefective pixel detection accuracyVSAvoidpixel value consistency

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent segments the correction process into two distinct parts: defective pixel correction and low saturation pixel correction. By separating these corrections and applying them in a specific sequence (defective pixel correction first, then low saturation pixel correction), the system avoids false detection of low saturation pixels as defective pixels, thereby improving both correction accuracy and pixel value uniformity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies defective pixel correction as a preliminary action before low saturation pixel correction. This preliminary correction establishes a baseline that prevents subsequent low saturation pixel correction from mistakenly identifying and correcting already-corrected defective pixels, thus improving measurement precision

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10791290B2Image processing apparatus, image processing method, and non-transitory computer readable recording medium

Publication Date: 2020.09.29 OLYMPUS CORPORATION(JP)

AI summary

An image processing apparatus is disclosed which processes noise resulting from a defective pixel different from a low saturation pixel, included in image data generated by an image sensor including a plurality of pixels two-dimensionally arranged to receive light from outside and generate a signal according to an amount of received light and including a plurality of read-out circuits that read out the signal as a pixel value. The image processing apparatus includes an acquisition unit that obtains the image data generated by the image sensor and a saturation level of each of the plurality of pixels; and a noise processing unit that processes the noise on the basis of the saturation level obtained by the acquisition unit.