Image Processing Edge Enhancement Saturation Correction

Solution Overview

Problem

Conventional edge enhancement processing often results in unnatural boundaries and unprinted portions, especially when enhancing images with high saturation characters or lines against low saturation backgrounds, making it difficult to achieve sufficient enhancement without adverse effects.

Innovation Solution

An image processing apparatus and method that adjusts pixel values post-edge enhancement based on image saturation, using a decision unit to determine correction values and a correction unit to modify pixel values, thereby controlling the amount of enhancement to prevent unnatural changes and unprinted portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If edge enhancement processing is performed with strong enhancement amount, then image sharpness is improved, but unnatural boundaries and color changes occur in high saturation regions

Engineering Contradiction:

Improveimage sharpnessVSAvoidunnatural boundary and color change

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies different enhancement strategies to different regions of the image based on saturation levels. High saturation regions (characters, lines) receive suppression or no enhancement, while low saturation regions (backgrounds, photos) receive full enhancement. This local differentiation resolves the contradiction by allowing sharpness improvement in appropriate regions without causing unnatural effects in sensitive high saturation regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically changes the enhancement parameter (enhancement amount) based on the saturation value of each pixel or region. By adjusting this parameter according to saturation levels, the system achieves sufficient enhancement for low saturation images while preventing adverse effects in high saturation images, thus resolving the contradiction between sharpness and natural appearance.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If edge enhancement processing is performed with suppressed enhancement amount, then unnatural boundaries are prevented in high saturation images, but sufficient enhancement is not achieved for images requiring it

Engineering Contradiction:

Improveunnatural boundary preventionVSAvoidenhancement sufficiency

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies different enhancement strategies to different regions of the image based on saturation levels. High saturation regions (characters, lines) receive suppression or no enhancement, while low saturation regions (backgrounds, photos) receive full enhancement. This local differentiation resolves the contradiction by allowing sharpness improvement in appropriate regions without causing unnatural effects in sensitive high saturation regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically changes the enhancement parameter (enhancement amount) based on the saturation value of each pixel or region. By adjusting this parameter according to saturation levels, the system achieves sufficient enhancement for low saturation images while preventing adverse effects in high saturation images, thus resolving the contradiction between sharpness and natural appearance.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If uniform edge enhancement is applied to all pixels, then processing simplicity is maintained, but adverse effects occur in specific saturation regions

Engineering Contradiction:

Improveprocessing simplicityVSAvoidadverse effect in saturation regions

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces saturation-based regional differentiation, dividing the image into high saturation and low saturation regions. This adds complexity to the processing logic but eliminates adverse effects by applying appropriate enhancement strategies to each region type, resolving the contradiction between simplicity and effectiveness.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent performs preliminary classification of pixels or regions based on saturation levels before applying enhancement. This preliminary action identifies which regions require enhancement and which should be suppressed, enabling the subsequent enhancement process to avoid adverse effects while maintaining overall processing efficiency.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9349161B2Image processing apparatus and image processing method with edge enhancement

Publication Date: 2016.05.24 CANON KK

AI summary

Edge enhancement processing is performed for the luminance of each pixel of an image, and the correction value of the pixel after the edge enhancement processing is decided according to the saturation of each pixel of the image. The value of the pixel after the edge enhancement processing is corrected using the decided correction value.