Color Image Noise Reduction via LAB Channel Segmentation

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Solution Overview

Problem

Conventional image processing systems using dilating and eroding processes on color images are susceptible to noise generation and fail to effectively eliminate noise, often producing 'false color' noises.

Innovation Solution

An image processing apparatus and method that receives color information for each pixel, derives characteristic values for target and proximate pixels, and replaces the color values of target pixels with those of proximate pixels based on their relationships, using a processing mask to reduce noise through dilating, eroding, or intermediate processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dilating/eroding process is applied to each of three image planes corresponding to three primary colors, then image processing is performed, but noise elimination is poor and false color noises are generated

Engineering Contradiction:

Improvenoise elimination capabilityVSAvoidfalse color noises

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent merges the dilating/eroding processing with color space conversion by processing the image in LAB color space instead of separate RGB planes. The L-channel (lightness) is processed with dilating/eroding operations while the a* and b* channels (color information) are preserved, thereby eliminating noise without generating false color effects.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the color image into separate channels (L, a*, b*) and applies different processing operations to each channel. The L-channel undergoes noise reduction through dilating/eroding, while the color channels (a*, b*) are maintained intact, achieving noise elimination without color distortion.

Inventive Principle:

Principle #1Segmentation

2Productivity

If conventional dilating/eroding process is applied to color images, then processing is simplified, but noise components are not effectively eliminated

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidnoise reduction effectiveness

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the color space parameter from RGB to LAB, where the L-channel represents lightness and is suitable for noise reduction operations. This parameter transformation enables effective noise elimination while maintaining processing efficiency, as the LAB space separates luminance and color information.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7684617B2Apparatus and methods for processing images

Publication Date: 2010.03.23 OMRON CORP

AI summary

In one embodiment, a system for processing an image receives color information including three variables representing a color of each of a plurality of pixels which constitute the image. The system derives a target characteristic value corresponding to a target pixel among the plurality of pixels based on the three variables of the target pixel. The system derives proximate characteristic values corresponding to a plurality of proximate pixels which are proximate to the target pixel. The system replaces the three variables of the target pixel with the three variables of one of the proximate pixels depending on a relationship between the target characteristic value and the proximate characteristic values.