Flashlight Control for Backlight Image Contrast

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Solution Overview

Problem

Camera-based mobile communication devices struggle with capturing images under backlight conditions, resulting in objects appearing darker compared to the background due to insufficient handling of strong background light.

Innovation Solution

Incorporating a light sensor, camera module, flashlight, and micro-processing unit (MPU) with comparison, face recognition, and flashlight control modules to detect brightness, recognize facial features, and adjust the flashlight's angle and intensity, along with GPS and electronic compass modules to calculate solar and photographing azimuths, thereby controlling the flashlight to mitigate backlight issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the camera module captures images under backlight conditions, then the background is well-illuminated, but the objects appear darker and photographic quality deteriorates

Engineering Contradiction:

Improvebackground illuminationVSAvoidphotographic quality

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The system detects backlight conditions in advance and activates the flashlight to illuminate the subject before the image is captured, counteracting the harmful effect of backlight on subject visibility

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The system uses the detected backlight condition as a trigger to activate the flashlight, converting the harmful backlight situation into a beneficial dual-lighting scenario where both ambient and artificial light work together

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Illumination intensity

If the flashlight is activated to illuminate the subject, then the subject brightness improves, but energy consumption increases

Engineering Contradiction:

Improvesubject brightnessVSAvoidenergy consumption

Core Design Contradiction:

Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The light sensor continuously monitors ambient light conditions and provides feedback to the control unit, which activates the flashlight only when backlight conditions are detected, optimizing energy usage based on real-time environmental data

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the operational state of the flashlight from off to on based on detected light parameters, activating illumination only when and where needed to minimize energy consumption

Inventive Principle:

Principle #35Parameter changes

3Illumination intensity

If the flashlight intensity is increased to compensate for backlight, then the subject illumination improves, but the contrast between subject and background becomes unbalanced

Engineering Contradiction:

Improvesubject illuminationVSAvoidbrightness balance

Core Design Contradiction:

Illumination intensityVSEase of operation

Solution Approach 1:

The flashlight provides partial illumination specifically targeted at the subject area rather than overwhelming the entire scene, achieving sufficient subject brightness while maintaining natural background appearance and balanced contrast

Inventive Principle:

Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution effectively reduces the contrast between objects and backgrounds in images taken under backlight conditions, ensuring better photographic quality by adjusting the flashlight's angle and intensity based on environmental and positional data.

Implementation Method 1

a light sensor... is operable to detect a brightness value of an external light source

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS8200075B1Camera-based mobile communication device and method for controlling flashlight thereof

Publication Date: 2012.06.12 ZHIGU HLDG

AI summary

A camera-based mobile communication device includes a light sensor, a camera module, a flashlight, and a micro-processing unit (MPU). The light sensor is operable to detect a brightness value of an external light source. The camera module is operable to photograph an image. The flashlight is operable to generate a flash. The MPU is electrically connected to the light sensor, the camera module, and the flashlight. The MPU includes a comparison module, a face recognizing module, and a flashlight control module. The comparison module is operable to compare the brightness value with a threshold brightness value. The face recognizing module is operable to determine whether there exists a facial feature in the image. The flashlight control module is operable to turn on the flashlight when the detected brightness value is greater than the threshold brightness value and the facial feature is recognized from the image.