Segmented Image Sensor for Extended Depth of Field
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for extending the depth of field in electronic image capture systems, such as focus stacking, wavefront coding, and plenoptic imaging, are impractical for portable and handheld devices due to requirements like tripod use, computational complexity, and component packaging constraints.
Innovation Solution
A method and apparatus that contemporaneously capture multiple images of a scene at different depth of field and image resolution settings, allowing for the formation of a composite image by selecting superior image information from each capture, using a digital imaging apparatus with a controllable aperture and image sensor array segmented into disjoint pixel subsets for independent readout timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If focus stacking is used to extend depth of field, then image resolution and focus quality are improved, but the method requires tripod support and is impractical for handheld devices
Solution Approach 1:
The sensor array is divided into multiple disjoint pixel subsets, each independently readable. This segmentation allows different subsets to capture images at different focal settings simultaneously, eliminating the need for sequential shooting and tripod support while maintaining extended depth of field capabilities
Solution Approach 2:
The system dynamically assigns different focal settings to different pixel subsets during a single exposure. The lens focal length is varied during the exposure period, with different subsets reading out at different focal settings, creating a dynamic capture process that achieves focus stacking without requiring multiple separate shots
2Reliability
If wavefront coding is used to extend depth of field, then image capture is possible, but computational complexity and circuitry requirements increase
Solution Approach 1:
Instead of using complex wavefront coding optics and processing, the system creates simplified copies of the imaging process across multiple pixel subsets. Each subset captures a simplified version of the scene at a different focal setting, and these are combined through straightforward selection rather than complex computational deconvolution
Solution Approach 2:
The system replaces expensive, complex wavefront coding circuitry and processing requirements with simpler, more economical pixel subset segmentation and basic image selection algorithms, reducing overall device complexity while achieving the same functional goal
3Loss of information
If plenoptic imaging is used to extend depth of field, then directional light information is captured, but component packaging becomes complex and difficult to adapt to narrow profiles
Solution Approach 1:
The sensor array is segmented into multiple disjoint pixel subsets that can be independently read out. This segmentation provides directional and focal information through simple spatial separation rather than complex plenoptic optics, making the design easier to manufacture and adapt to narrow device profiles
Solution Approach 2:
The invention extracts only the essential information needed for extended depth of field (focal settings at different depths) by having different pixel subsets read out at different focal settings, rather than capturing complete plenoptic data. This extraction approach reduces packaging complexity while maintaining the core functionality
4Measurement precision
If multiple full resolution images are captured at different focal settings, then depth of field is extended, but motion artifacts increase
Solution Approach 1:
Multiple images captured at different focal settings are merged into a single composite image by selecting the in-focus portions from each. This merging process creates an extended depth of field image while minimizing motion artifacts because the selection process naturally chooses the sharpest regions from each focal setting
Solution Approach 2:
The system changes the focal setting parameter during the exposure period for different pixel subsets. By varying the focal length dynamically and having different subsets read out at different settings, the system captures multiple focal planes in a single continuous operation, reducing motion-induced inconsistencies
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 enables improved depth of field in digital imaging devices, particularly suitable for handheld cameras, by combining images with different f/# settings to enhance resolution and focus, reducing motion artifacts and computational complexity, while maintaining a compact design.
Implementation Method 1
each individual pixel providing a signal based on the light level of the portion of a scene image projected onto the pixel by a lens
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for forming an image, implemented at least in part by a data processing apparatus, by obtaining a first image of a scene from a first subset of pixels in an image sensor array at a first f/# setting, adjusting the imaging optics that obtain light from the scene at a second f/# setting, obtaining a second image of the scene from a second subset of pixels in the image sensor array, and forming a composite image by combining image data from at least the first and second images.