Tone Correction Curve Control for Image Contrast

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Solution Overview

Problem

Conventional image pickup apparatuses fail to ensure user satisfaction with image quality during tone correction in foggy or misty conditions, as the degree of correction is determined by the luminance histogram without considering user preferences.

Innovation Solution

An image pickup apparatus with a tone correction unit that allows users to set correction intensity parameters for determining coordinate values on the correction curve, enabling the generation of a new correction curve by multiplying a pre-stored curve with a user-generated tone curve, thereby allowing users to adjust the degree of correction effect and achieve desired image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If tone correction is performed using a luminance histogram, then image contrast is improved, but user satisfaction with image quality cannot be ensured

Engineering Contradiction:

Improveimage contrastVSAvoiduser satisfaction

Core Design Contradiction:

Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent makes the correction curve dynamic and adjustable by allowing users to modify control point coordinates and correction intensity parameters. The system transitions from a fixed automated correction process to an adaptable one where users can dynamically adjust the correction characteristics to match their preferences while maintaining the contrast improvement benefit.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent enables parameter changes by allowing users to adjust control point coordinates (x, y values) and correction intensity parameters. This gives users direct control over the correction curve characteristics, enabling them to optimize image quality according to their preferences while preserving the contrast enhancement achieved through histogram-based correction.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If correction parameters are automatically determined from luminance histogram, then processing speed is maintained, but image quality cannot be customized

Engineering Contradiction:

Improveprocessing speedVSAvoidimage quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-defining control points on the correction curve that users can later adjust. This framework allows users to customize image quality without starting from scratch, maintaining processing efficiency while enabling quality customization through the adjustable control point system.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9715722B2Image pickup apparatus that performs tone correction, control method therefor, and storage medium

Publication Date: 2017.07.25 CANON KK

AI summary

An image pickup apparatus which is capable of setting image quality as desired by a user when performing tone correction according to a luminance histogram of a taken image. A luminance histogram obtaining unit obtains a luminance histogram from image data. A luminance tone correction unit performs tone correction on the image data using a correction curve generated based on the obtained luminance histogram. A user setting unit receives a setting as to a correction intensity of the tone correction from the user and sets parameters for determining coordinate values of control points on the correction curve. A luminance tone control unit generates the correction curve based on the luminance histogram and determines the coordinate value according to the parameters set by the user setting unit.