Image Processing Device Banding Correction
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Solution Overview
Problem
The existing technologies fail to effectively prevent the clarification of original grayscale variations in images with smooth gradations, leading to the generation of banding phenomena during display, which results in unclear gradations and visible band-like artifacts.
Innovation Solution
An image processing device and method that assesses the possibility of banding generation based on color distribution in a noted area, adjusts the color of target pixels through a correction process, and outputs a corrected image to minimize banding. The correction amount varies according to an evaluation value, with options to either not correct or correct the pixel color based on a threshold comparison, and can adjust the correction amount based on the difference between the evaluation value and a threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a smoothing process is performed to diminish banding, then banding is reduced, but the variation of grayscale becomes unclear
Solution Approach 1:
The patent applies local quality by performing smoothing only in specific regions where banding is detected, rather than uniformly across the entire image. The evaluation value determining unit calculates an evaluation value for each pixel based on its surrounding area's color distribution, and smoothing is selectively applied only when the evaluation value exceeds a threshold, thus preserving grayscale variations in regions where they are important while reducing banding where it occurs.
Solution Approach 2:
The patent implements dynamics by making the smoothing process adaptive and variable rather than static. The correction amount varies dynamically based on the evaluation value, which is calculated for each pixel based on local color distribution characteristics. This allows the smoothing intensity to be adjusted locally for each pixel, enabling the system to respond to different regions' needs and preserve important grayscale variations while reducing banding.
2Object-affected harmful factors
If color correction is applied to all pixels, then banding is reduced, but processing complexity increases
Solution Approach 1:
The patent applies partial action by performing color correction only on pixels that are determined to require smoothing based on their evaluation values. Instead of applying correction to all pixels in the image, the system selectively processes only those pixels where the evaluation value exceeds the threshold, thus reducing the overall processing complexity while still effectively addressing banding in the necessary regions.
3Object-affected harmful factors
If strong smoothing is applied, then banding is significantly reduced, but natural grayscale transitions are lost
Solution Approach 1:
The patent implements dynamics by making the smoothing intensity variable rather than uniform. The correction amount is determined dynamically based on the evaluation value for each pixel, which reflects the local color distribution characteristics. This allows strong smoothing to be applied only where banding is severe (high evaluation value) while maintaining natural grayscale transitions in regions where the evaluation value is lower, thus preserving grayscale accuracy where it matters.
Solution Approach 2:
The patent applies local quality by tailoring the smoothing strength to local conditions. Different regions of the image receive different correction amounts based on their specific color distribution characteristics as captured by the evaluation value. This ensures that strong smoothing is applied locally only where banding is problematic, while preserving the natural quality of grayscale transitions in regions where they are important.
Data Source
AI summary
To prevent any variation of the grayscale to be originally present from becoming unclear, diminishing banding that is generated when an image including a gradation is displayed. An image processing device obtains image data of an original image including plural pixels, obtains an evaluation value that represents the possibility of the generation of the banding on the basis of the color distribution of a noted area including a target pixel that is any one of the plural pixels, produces an intermediate image of which the color of the target pixel is corrected on the basis of the evaluation value, and causes a corrected image to be output on the basis of the produced intermediate image. A correction amount of the color of the target pixel is varied in accordance with the evaluation value, in the correction of the color.