Multi-Channel Camera Dynamic Range Expansion via Segmented Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional digital cameras face limitations in capturing scenes with high dynamic range due to the finite charge storage capacitance in pixels, leading to inadequate representation of light levels across varying illumination conditions, resulting in undesirable temporal aliasing and data loss.
Innovation Solution
The implementation of multiple camera channels with independent signal integration times, each operating on a semiconductor substrate, allows for simultaneous image capture of the same field of view with different exposure times, enabling the combination of data to form a composite image with a significantly expanded dynamic range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If multiple images are taken at different exposure times and then merged, then the dynamic range is increased, but temporal aliasing occurs when the scene or camera is moving
Solution Approach 1:
The image sensor array is divided into multiple independent regions, each capable of simultaneous image capture with different exposure times. This segmentation allows multiple exposure images to be captured concurrently rather than sequentially, eliminating temporal aliasing while maintaining expanded dynamic range through the combination of regional data.
2Loss of information
If the dynamic range is increased to accommodate highly varying illumination, then scenes with mixed shadows and bright sunshine can be captured, but the pixel noise level becomes a limiting factor
Solution Approach 1:
Data from multiple sensor regions with different exposure times are merged to form a composite image. By combining the information from regions that captured different exposure levels simultaneously, the system achieves expanded dynamic range while averaging out random noise, thereby improving measurement precision in the final composite image.
3Loss of information
If a single image sensor is used with multiple exposure times, then the dynamic range is expanded, but the images are not captured concurrently leading to temporal aliasing
Solution Approach 1:
The sensor array is segmented into multiple independent capture regions that operate simultaneously. Each region captures an image at a different exposure time during the same time interval, enabling concurrent capture of multiple exposure images and eliminating the temporal delay that causes aliasing in sequential capture methods.
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 effectively increases the dynamic range of digital cameras from approximately 70 dB to 90 dB, allowing for the detection of both dark and bright objects within a single frame without temporal aliasing, thereby improving image quality across diverse lighting conditions.
Implementation Method 1
Image sensors can be realized with semiconductors based on their capability to convert locally impinging light energy into a proportional amount of electronic charge
Data Source
AI summary
A digital camera includes a plurality of channels and a processing component operatively coupled to the plurality of channels. Each channel of the plurality of channels includes an optics component and a sensor that includes an array of photo-detectors. The processing component is configured to separately control an integration time of each channel, where a first integration time of a first channel is less than a second integration time of a second channel. The processing component is also configured to combine data from the plurality of channels to generate an image.