Selective Image Processing for Tone-Jump Correction

Solution Overview

Problem

Existing image processing techniques that reduce tone jumps also smooth portions that are not tone jumps, leading to a decrease in sharpness.

Innovation Solution

An image processing device and method that determine the presence of tone jumps by comparing average pixel values within specific pixel groups and only correct tone jumps when no contours or patterns are detected, using low-pass filters or noise addition to maintain sharpness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If smoothing processing is applied to reduce tone jump, then tone jump is reduced, but sharpness of non-tone jump portions is reduced

Engineering Contradiction:

Improvetone jump reductionVSAvoidsharpness

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent applies different processing treatments to different regions of the image based on local characteristics. Tone jump portions are identified and subjected to smoothing processing, while non-tone jump portions maintain their original sharpness. This is achieved by detecting edges and determining whether each pixel belongs to a tone jump region before applying correction, thereby making the processing quality location-specific rather than uniform across the entire image.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If smoothing processing is applied to reduce tone jump, then tone jump is reduced, but image quality is degraded

Engineering Contradiction:

Improvetone jump reductionVSAvoidimage quality

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies different processing treatments to different regions of the image based on local characteristics. Tone jump portions are identified and subjected to smoothing processing, while non-tone jump portions maintain their original sharpness. This is achieved by detecting edges and determining whether each pixel belongs to a tone jump region before applying correction, thereby making the processing quality location-specific rather than uniform across the entire image.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses edge detection and pixel value comparison to determine whether smoothing should be applied to each pixel. By comparing pixel values with neighboring pixels and detecting edges, the system provides feedback control that prevents smoothing in regions where it would degrade image quality, thereby maintaining overall image quality while still reducing tone jumps where appropriate.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12462349B2Image processing device and method suppressing image sharpness decrease while reducing a tone jump

Publication Date: 2025.11.04 PANASONIC PROJECTOR & DISPLAY CORPORATION

AI summary

An image processing device includes: the determination unit that determines whether or not, among a plurality of pixels arranged linearly including a pixel of interest, a first adjacent pixel, and a second adjacent pixel, there is a pixel having a pixel value whose difference from a pixel value of the pixel of interest is greater than or equal to a reference value; a tone jump determination unit that determines whether or not a difference between an average value of pixel values of the first pixel group and an average value of pixel values of the second pixel group is less than or equal to a first threshold; and a correction unit that corrects atone jump of at least one pixel among the plurality of pixels.