Asymmetric Exposure Time Adjustments for Multi-Frame HDR Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In low light conditions, multi-frame high dynamic range (HDR) image processing often results in images appearing darker due to the interference between short and long exposure frames, as short exposure frames occupy time that could be allocated to long exposure frames, which provide better results.
Innovation Solution
The technique dynamically adjusts exposure times asymmetrically by maintaining the exposure time for short exposure frames while increasing the exposure time for long exposure frames, achieved through sensor blanking and frame line length adjustments, thereby refraining from altering the short exposure frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If short exposure frames are captured in multi-frame HDR imaging, then frame rate is maintained, but long exposure frame quality deteriorates in low light conditions
Solution Approach 1:
The patent applies asymmetry by differentially adjusting exposure times for short and long exposure frames based on light conditions. In low light conditions, the system increases long exposure time while maintaining or decreasing short exposure time, creating an asymmetric exposure strategy that optimizes each frame type for its specific purpose rather than applying uniform exposure adjustments
Solution Approach 2:
The system dynamically adjusts exposure times based on detected light conditions. The exposure time for long exposure frames is increased when low light is detected, while short exposure frame timing remains unchanged. This dynamic adaptation allows the system to optimize image quality for each frame type according to ambient lighting conditions
2Manufacturing precision
If exposure time for long exposure frames is increased, then image quality in low light improves, but processing time and power consumption increase
Solution Approach 1:
The patent applies local quality by selectively increasing exposure time only for long exposure frames while maintaining short exposure frame timing. This targeted approach concentrates the time investment where it provides maximum benefit (low light capture) without proportionally increasing processing time for all frames, thus improving image quality efficiently
3Device complexity
If symmetric exposure time adjustment is applied to both short and long exposure frames, then processing simplicity is maintained, but image quality in low light conditions deteriorates
Solution Approach 1:
The patent directly addresses this contradiction by implementing asymmetric exposure time adjustment where long exposure frames receive increased exposure time in low light conditions while short exposure frames maintain their original timing. This asymmetric approach prioritizes image quality for the frame type that benefits most from extended exposure, accepting increased processing complexity as necessary for optimal performance
Data Source
AI summary
Methods, systems, and devices for asymmetric exposure time adjustments for multi-frame (MF) high dynamic range (HDR) imaging in low light conditions are described. In some implementations, a device may receive a set of frames including short exposure frames associated with a first exposure time and long exposure frames associated with a second exposure time and may adjust the second exposure time associated with the long exposure frames to obtain a third exposure time for the long exposure frames based on detecting a low light condition associated with the set of frames. The device may adjust the second exposure time associated with the long exposure frames to obtain the third exposure time for the long exposure frames based on adding, at an image sensor of the device, an additional set of blanking lines to a set of visible lines associated with the short exposure frames.