Artificial-Light Flicker Synchronization for Multi-Source Photography
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Solution Overview
Problem
Existing photographing methods fail to effectively eliminate bright and dark streaks in captured images caused by multiple artificial light sources with varying flicker frequencies, which is not addressed by existing solutions designed for single-source flicker.
Innovation Solution
An electronic device determines the flicker frequencies of multiple artificial light sources and adjusts exposure time and frame intervals to an integer multiple of the dominant flicker frequency, while maintaining ISO within a preset range, to mitigate the banding phenomenon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If exposure time is adjusted to an integer multiple of the flicker period of a single artificial light source, then the banding phenomenon caused by that single light source is eliminated, but the banding phenomenon caused by other artificial light sources with different flicker frequencies cannot be resolved
Solution Approach 1:
The patent segments the problem by identifying and treating different flicker frequency components separately. It detects multiple flicker frequencies in the photographing environment and selectively applies exposure time adjustments based on the dominant flicker frequency, rather than attempting to simultaneously address all frequencies. This segmentation allows the system to eliminate banding from the primary light source while managing the impact of secondary sources.
Solution Approach 2:
The patent dynamically changes the exposure time parameter based on detected flicker frequencies. It adjusts the exposure time to be an integer multiple of the dominant flicker period, and also modifies the frame interval parameter to coordinate with the flicker characteristics. These parameter changes are adapted according to the specific photographing environment, enabling effective banding reduction across multiple light source scenarios.
2Object-affected harmful factors
If exposure time is extended to align with flicker periods, then banding is reduced, but frame rate and productivity decrease
Solution Approach 1:
The patent implements dynamic adjustment of exposure time and frame interval based on real-time detection of flicker frequencies. Rather than using a fixed extended exposure time, the system adaptively sets these parameters to the minimum values required to align with the dominant flicker period. This dynamic approach reduces banding while minimizing the impact on frame rate, allowing the system to maintain higher productivity when possible.
Solution Approach 2:
The patent utilizes periodic action by synchronizing the exposure time and frame interval with the periodic flicker of artificial light sources. It detects the flicker frequency and sets the exposure time to be an integer multiple of the flicker period, creating a periodic synchronization that eliminates banding. The frame interval is also adjusted periodically to maintain coordination with the light source flicker, achieving banding reduction without excessive exposure time extension.
Data Source
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AI summary
This application provides a photographing method from a plurality of artificial light sources and a related apparatus. An electronic device may determine flicker frequencies of the plurality of artificial light sources, and select two of the flicker frequencies, denoted as F1 and F2. Flicker periods corresponding to F1 and F2 are denoted as T1 and T2, respectively. If an integer multiple of T1 is within a first range, an exposure time is adjusted to the integer multiple of T1, and a frame interval is adjusted based on F2. If the integer multiple of T1 is not within the first range but an integer multiple of T2 is within the first range, the electronic device adjusts the exposure time to the integer multiple of T2 and adjusts the frame interval based on F1; otherwise, the electronic device only adjusts the frame interval based on F1. The method can eliminate a banding phenomenon caused by a single artificial light source and attenuate a banding phenomenon caused by other artificial light sources, avoiding scrolling bright and dark streaks in images on the electronic device.