White Balance Processing Stabilizes Preview Tone During Camera Shake

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

When a camera is shaken, the main light source frequently switches among multiple light sources, causing variations in the tone of preview images with white balance corrections, leading to a poor user experience.

Innovation Solution

A white balance processing method that determines the color temperature of the main light source for each frame image and performs white balance processing based on the color temperature of the adjacent previous frame image if the variation is less than a predetermined threshold, preventing frequent switches of the main light source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the main light source is detected by processing each frame image independently, then the white balance can be adjusted according to the current light source, but the main light source frequently switches when the camera is shaken, causing tone variations in preview images

Engineering Contradiction:
Improvewhite balance adaptation to different light sourcesVSAvoidtone consistency of preview images
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by detecting and determining the main light source in advance (in the first frame image) before the camera shaking occurs, then reusing this predetermined main light source for subsequent frame images during shaking. This prevents frequent switching of main light source detection while maintaining adaptive white balance adjustment, thereby stabilizing the tone of preview images even when the camera is shaken.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the white balance is adjusted for each frame image based on detected light source, then the white balance can be accurate for current lighting conditions, but the processing complexity increases due to frequent light source detection and switching

Engineering Contradiction:
Improvewhite balance accuracyVSAvoidlight source detection and switching logic
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary detection and determination of the main light source in advance (in the first frame image), then reuses this predetermined main light source for subsequent frame images during shaking periods. This eliminates the need for continuous light source detection and switching logic during shaking, reducing processing complexity while maintaining white balance accuracy through the previously determined main light source.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If the main light source switching is prevented by using adjacent frame's color temperature, then the tone variation is reduced, but the white balance may become less accurate when the light source actually changes

Engineering Contradiction:
Improvetone consistencyVSAvoidwhite balance accuracy
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the main light source determination adaptive: it uses the predetermined main light source from adjacent frames during shaking periods to maintain tone consistency, but allows the main light source to be重新detected and updated when the camera stabilizes or when lighting conditions genuinely change. This dynamic switching between using predetermined and newly detected main light sources balances tone stability with white balance accuracy.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3477942B1White balance processing method, electronic device and computer readable storage medium
Publication Date: 2020.08.05 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP3477942B1 patent drawingFigure 1~2
  • EP3477942B1 patent drawingFigure 3~4
  • EP3477942B1 patent drawingFigure 5~6

AI summary

The present disclosure provides a white balance processing method. The white balance processing method includes the followings. Each image of the plurality of successive frame images each subjected to a color temperature variation is processed to determine color temperature corresponding to a main light source (S11). It is determined whether a variation of primary color temperature is greater than or equal to a predetermined threshold (S12). The variation of primary color temperature refers to a difference between the color temperature of the main light source in a second frame image and the color temperature of the main light source in a first frame image. The first frame image and the second frame image are two frame images adjacent to each other and from the plurality of successive frame images. The white balance process is performed on the second frame image according to the color temperature of the main light source in the first frame image when the variation of primary color temperature is less than the predetermined threshold (S13).