Camera Image Processing for Flicker Banding and Color Cast Removal
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Solution Overview
Problem
When photographing a moving object under a flicker light source, electronic devices experience motion blur and banding phenomena, leading to poor image quality due to shortened exposure times and mismatched LSC gain information, resulting in color overcorrection.
Innovation Solution
An image processing method that adjusts exposure times to capture images with banding and color cast regions removed by using a color transformation matrix and brightness parameter, ensuring accurate lens shading correction and avoiding color overcorrection through statistical LSC gain information matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the exposure time is shortened to reduce motion blur, then the photosensitivity value increases and motion blur is reduced, but the exposure time does not satisfy an integer multiple of 10 ms, resulting in banding phenomenon and poor image quality
Solution Approach 1:
The patent applies dynamics by making the exposure time adjustable and adaptive based on the flicker frequency of the light source. The system dynamically selects exposure times that are integer multiples of the flicker period (e.g., 10ms for 50Hz AC lighting), resolving the contradiction between short exposure time for motion clarity and proper synchronization to avoid banding. This allows the exposure time to be optimized for both speed and image quality under flicker conditions.
2Manufacturing precision
If LSC processing is performed on the first image with mismatched LSC gain information, then lens shading correction is applied, but color overcorrection occurs due to mismatched LSC gain information
Solution Approach 1:
The patent applies preliminary action by capturing a second image with an exposure time that is an integer multiple of the flicker period (e.g., 10ms) before processing the first image. This second image is used to generate accurate LSC gain information that is then applied to correct the first image. By preparing the correction parameters in advance from a properly synchronized image, the system avoids color overcorrection while maintaining accurate lens shading correction.
Solution Approach 2:
The patent uses the second image as an intermediary to transfer accurate LSC gain information to the first image processing pipeline. The second image, captured with exposure time synchronized to the flicker frequency, serves as a mediator that provides correct shading correction parameters, which are then applied to the first image to avoid direct color overcorrection issues.
3Manufacturing precision
If the exposure time is set to an integer multiple of 10 ms to avoid banding, then the banding phenomenon is reduced, but the photosensitivity value decreases and motion blur increases
Solution Approach 1:
The patent resolves this contradiction by dynamically selecting different exposure times for different images in a sequence. The first image uses a shorter exposure time optimized for motion clarity, while the second image uses an exposure time that is an integer multiple of the flicker period to avoid banding. The system then uses the second image's LSC gain information to correct the first image, achieving both motion clarity and banding-free results through adaptive timing.
Data Source
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AI summary
This application relates to the field of images, and provides an image processing method and an electronic device. The image processing method includes: enabling a camera application; displaying a first image, where the first image includes banding and/or a color cast image region; detecting a first operation; capturing a second image in response to the first operation; obtaining a color transformation matrix and/or a brightness parameter based on the first image and the second image; performing first image processing on the first image based on the color transformation matrix and/or the brightness parameter, to obtain a third image, where the third image is an image with the banding and/or the color cast image region removed; acquiring a first parameter based on brightness information of the second image; performing lens shading correction processing on the third image based on the first parameter, to obtain a fourth image; and displaying or storing the fourth image. According to the solutions of this application, when a moving object is photographed, banding and/or a local color cast in an image can be removed, and color overcorrection in the image can be avoided, thereby improving image quality.