Image Contrast Correction via Local Reflection Amplitude
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Solution Overview
Problem
Conventional Multi-Scale Retinex methods fail to appropriately correct image contrast when the amplitude of the reflection rate differs across local areas of an image.
Innovation Solution
An image processing device and method that includes a signal intensity extraction unit, a peripheral region reference value calculator, and an emphasis degree determination unit to calculate and apply a corrected reflection rate based on local maxima or minima within defined regions of interest, ensuring appropriate contrast correction across varying reflection rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If uniform normalization is applied in the Multi-Scale Retinex method, then the processing is simple and fast, but the contrast correction is inappropriate when the amplitude of reflection rate differs for each local area
Solution Approach 1:
The patent applies local quality by determining emphasis degrees independently for each local area based on its specific reflection rate characteristics. The emphasis degree determination unit calculates different emphasis degrees for different regions, allowing each local area to be corrected according to its own amplitude characteristics rather than applying a uniform normalization across the entire image.
2Device complexity
If uniform normalization is applied in the Multi-Scale Retinex method, then the processing is simple, but the contrast correction is inappropriate when the amplitude of reflection rate differs for each local area
Solution Approach 1:
The patent introduces local quality by making the emphasis degree spatially variable. Each local area undergoes contrast correction with an emphasis degree tailored to its reflection rate amplitude, achieving accurate local contrast correction while maintaining reasonable processing complexity through the structured approach of calculating reference values and emphasis degrees systematically.
Solution Approach 2:
The patent segments the image processing into distinct functional units: signal intensity extraction unit, peripheral region reference value calculator, emphasis degree determination unit, and conversion output unit. This segmentation allows the complex task of adaptive contrast correction to be broken down into manageable steps, balancing processing complexity with correction accuracy.
3Manufacturing precision
If non-uniform emphasis degree is applied to areas with different reflection rates, then the contrast correction is appropriate, but the processing complexity increases
Solution Approach 1:
The patent implements local quality by calculating emphasis degrees specific to each local area's reflection rate characteristics. The emphasis degree determination unit uses the reference value from the peripheral region calculator to determine appropriate emphasis degrees for different areas, achieving accurate contrast correction tailored to local amplitude variations.
Solution Approach 2:
The patent employs feedback by using the calculated reference value from the peripheral region to adjust the emphasis degree determination. The system continuously adapts the emphasis degree based on the local reflection rate characteristics, creating a feedback loop that ensures accurate contrast correction while managing processing complexity through systematic adaptation.
Data Source
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AI summary
The present invention provides an image processing device, an image processing method, and an image processing program capable of appropriately correcting contrast even for an image in which the amplitude of the reflection rate differs for each local area of the image. The present invention provides an image processing device, comprising: a signal intensity extraction unit configured to extract signal intensity of an input image; a peripheral region reference value calculator configured to calculate a peripheral region reference value based on the signal intensity of a peripheral region located around a small region of interest; and an emphasis degree determination unit configured to determine an emphasis degree of the signal intensity so as to increase the signal intensity of the small region, wherein the signal intensity is defined as a reflection rate in the input image input to the image processing device, the small region is defined as a region which is a part of the input image and comprises at least one pixel, and the emphasis degree is monotonically non-decreasing with respect to a difference between the peripheral region reference value and a predetermined value.