Under-screen Camera Image Quality via Screen Influence Subtraction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Under-screen cameras in terminal devices face challenges in capturing high-quality images due to the influence of screen luminance from OLED or LCD displays, which affects the quality of external ambient light acquisition.

Innovation Solution

A method and apparatus that determine the screen influence value using a light sensor and subtract it from the optical signal value acquired by the camera, allowing for the generation of images that accurately represent the external ambient light, thereby reducing the impact of screen luminance and improving image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If an under-screen camera is used to achieve full-screen display, then the screen area is improved, but the image quality deteriorates due to screen luminance influence

Engineering Contradiction:
Improvescreen areaVSAvoidimage quality
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent extracts the harmful screen luminance influence from the camera's optical signal by using a light sensor to detect the screen's light emission characteristics. The detected screen influence is then separated and removed from the camera's captured signal, allowing the camera to capture only the external ambient light information, thus resolving the contradiction between full-screen area and image quality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a light sensor as an intermediary device to measure the screen luminance influence. This intermediary component enables the system to quantify and compensate for the screen's harmful effect on the camera, allowing the camera to function as if it were in a dark environment while maintaining full-screen display capabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If the screen luminance is increased to improve display brightness, then the display quality is improved, but the camera's ability to capture external light deteriorates

Engineering Contradiction:
Improvedisplay brightnessVSAvoidexternal light capture accuracy
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the light sensor continuously monitors the screen luminance and feeds this information back to the camera processing system. Based on this feedback, the system dynamically adjusts and subtracts the screen influence from the camera's captured signal, enabling the camera to accurately capture external light regardless of the display brightness level.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameter processing approach by introducing a screen influence value that is subtracted from the camera's optical signal. This parameter transformation allows the system to maintain accurate external light measurement even when the display brightness parameter is high, effectively decoupling the two conflicting requirements.

Inventive Principle:
Principle #35Parameter changes

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 approach enables the generation of more realistic and high-quality images by isolating the ambient light signal from the screen's influence, enhancing the photography experience in terminal devices with under-screen cameras.

Implementation Method 1

a second optical signal value that is acquired for the display screen of a current luminance by the light sensor

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

a first optical signal value that is acquired by the camera at the time of photographing

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3975548B1Photographing method and apparatus, terminal, and storage medium
Publication Date: 2024.06.12 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3975548B1 patent drawingFigure 1
  • EP3975548B1 patent drawingFigure 2
  • EP3975548B1 patent drawingFigure 3

AI summary

The present disclosure relates to a photographing method and apparatus, a terminal, and a storage medium. The method is applied to a terminal including a camera and a display screen, the camera being disposed under the display screen, the method including: determining a first optical signal value acquired by the camera at the time of photographing; determining a screen influence value of the display screen based on at least a second optical signal value acquired by a light sensor; and generating an image based on the first optical signal value and the screen influence value. By this method, the terminal device can better eliminate influence of the screen backlight, and thus the generated image is more realistic.