Exposure Control Method for Night Scene Image Quality

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Solution Overview

Problem

Mobile terminal devices struggle to capture high-quality images in night scenes due to low dynamic range and high noise levels, caused by low ambient light luminance, leading to poor user experience.

Innovation Solution

An exposure control method that determines target exposure based on ambient light luminance, adjusts exposure time and photo-sensitivity, and updates exposure time when it exceeds a certain limit to improve image quality, reducing noise and enhancing brightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If exposure time is increased to improve image brightness in low light conditions, then image brightness is improved, but image shake and blur increase

Engineering Contradiction:
Improveimage brightnessVSAvoidimage stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The system performs preliminary detection of ambient light luminance and shake degree before capturing the image. Based on these detections, it pre-calculates and sets the optimal exposure time and photo-sensibility parameters, ensuring that the exposure time does not exceed the upper limit that would cause noticeable shake, thus preventing blur before it occurs

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts exposure parameters (exposure time and photo-sensibility) based on detected ambient light conditions and shake degree. By changing these parameters adaptively and setting an upper limit on exposure time, the system improves image brightness while maintaining image stability

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If photo-sensibility is increased to improve image brightness, then image brightness is improved, but noise level increases

Engineering Contradiction:
Improveimage brightnessVSAvoidnoise level
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts photo-sensibility based on ambient light luminance detection. By optimizing the photo-sensibility parameter according to actual lighting conditions and combining it with controlled exposure time within the upper limit, the system achieves improved image brightness while suppressing noise generation

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If exposure time is extended to capture more light, then dynamic range is improved, but image shake becomes noticeable

Engineering Contradiction:
Improvedynamic rangeVSAvoidimage stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The system performs preliminary detection of ambient light luminance and shake degree before capturing the image. Based on these detections, it pre-calculates and sets the optimal exposure time and photo-sensibility parameters, ensuring that the exposure time does not exceed the upper limit that would cause noticeable shake, thus preventing blur before it occurs

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts exposure parameters (exposure time and photo-sensibility) based on detected ambient light conditions and shake degree. By changing these parameters adaptively and setting an upper limit on exposure time, the system improves image brightness while maintaining image stability

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3624438B1Exposure control method, and electronic device
Publication Date: 2023.12.06 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP3624438B1 patent drawingFigure 1
  • EP3624438B1 patent drawingFigure 2~3
  • EP3624438B1 patent drawingFigure 4~5

AI summary

The disclosure provides an exposure control method, an exposure control device, an electronic device and a computer readable storage medium. The method includes: determining (101) a target exposure for an image to be captured based on ambient light luminance; determining (102) an exposure time for the image to be captured based on the target exposure and a preset photo-sensibility for the image to be captured; in response to determining that the exposure time for the image to be captured is greater than an upper limit, updating (103) the exposure time for the image to be captured based on the upper limit; and performing (104) an exposure control based on the exposure time and the photo-sensibility for the image to be captured.