Saturation Histogram Processing for Video Color Gradation

Solution Overview

Problem

Existing image processing methods struggle to distinguish between low and high saturation areas and intermediate saturation areas, leading to inadequate saturation enhancement and limited color gradation expression, especially in video display apparatuses with narrow color reproduction ranges.

Innovation Solution

An image processing apparatus comprising a color feature quantity calculation unit, saturation histogram generating unit, saturation conversion function generating unit, and saturation conversion unit, which calculates and converts saturation for each pixel based on a saturation histogram, allowing for proper enhancement of saturation and high color gradation expression regardless of saturation distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If saturation enhancement is applied to all areas including high saturation areas, then color vividness is improved, but color collapse occurs and subtle color differences are lost

Engineering Contradiction:

Improvecolor vividnessVSAvoidcolor differentiation precision

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent applies different saturation enhancement strategies to different saturation regions. Specifically, it enhances saturation in low and intermediate saturation areas while suppressing or maintaining saturation in high saturation areas, thereby achieving local optimization that prevents color collapse while improving overall color vividness

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the saturation enhancement coefficient based on the input saturation value. By changing the enhancement parameter according to the local saturation level, it achieves adaptive saturation control that improves color vividness where needed while preventing color collapse in already saturated regions

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If saturation enhancement is not applied to high saturation areas, then color collapse is prevented, but color gradation expression is limited and the merits of wide color reproduction range cannot be fully utilized

Engineering Contradiction:

Improvecolor differentiation precisionVSAvoidcolor gradation expression capability

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies different saturation enhancement strategies to different saturation regions. Specifically, it enhances saturation in low and intermediate saturation areas while suppressing or maintaining saturation in high saturation areas, thereby achieving local optimization that prevents color collapse while improving overall color vividness

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the saturation enhancement coefficient based on the input saturation value. By changing the enhancement parameter according to the local saturation level, it achieves adaptive saturation control that improves color vividness where needed while preventing color collapse in already saturated regions

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If average saturation value is used for saturation enhancement, then processing is simplified, but video consisting of low saturation areas and high saturation areas cannot be distinguished from video consisting only of intermediate saturation areas

Engineering Contradiction:

Improveprocessing complexityVSAvoidsaturation distribution discrimination accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the saturation histogram into multiple regions (low saturation area, intermediate saturation area, and high saturation area) based on predetermined threshold values. This segmentation enables the system to distinguish between different saturation distributions and apply appropriate enhancement strategies to each region, thereby achieving accurate discrimination of video characteristics

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the saturation enhancement coefficient based on the input saturation value. By changing the enhancement parameter according to the local saturation level, it achieves adaptive saturation control that improves color vividness where needed while preventing color collapse in already saturated regions

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10003720B2Image processing apparatus and method, and program and recording medium

Publication Date: 2018.06.19 MITSUBISHI ELECTRIC CORP

AI summary

Based on a histogram of saturation of an input video, a saturation conversion function is determined, and, referring to the determined saturation conversion function, the saturation of each pixel of the input video is converted. Alternatively, a saturation conversion coefficient determination function is generated from the histogram, a saturation conversion coefficient is determined from the saturation conversion coefficient determination function and the saturation, and color differences are multiplied by the determined saturation conversion coefficient. Regardless of what saturation distribution the input video has, the saturation can be properly enhanced, and at the same time a high gradation expression can be obtained.