Imaging Device Motion-Aware HDR Signal Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging devices struggle to generate high dynamic range (HDR) images when the relative position between the object and the imaging device changes during capturing, as they rely on replacing saturated pixel values from one image with processed values from another, leading to unsuitable pixel values and residual images.
Innovation Solution
An imaging device that outputs two signals based on different exposure periods, with a detection unit to assess changes in relative position and an image generation unit that selects the appropriate signal for each pixel, determining saturation and using motion detection to decide between the signals for HDR composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If two images are acquired at different timings to generate HDR, then high dynamic range is achieved, but pixel values become inaccurate when the object moves during acquisition
Solution Approach 1:
The patent segments the pixel array into multiple regions, with some pixels capturing long-exposure images and others capturing short-exposure images simultaneously. This spatial segmentation allows both long and short exposure images to be acquired at the same time, eliminating motion-related inaccuracies while maintaining HDR capabilities.
Solution Approach 2:
The patent dynamically selects which signal (long-exposure or short-exposure) to use for each pixel based on saturation detection and motion detection results. This dynamic selection process ensures that accurate pixel values are chosen for moving objects while preserving HDR information for static regions.
2Use of energy by moving object
If a long exposure period is used to capture dark regions, then sensitivity to dark areas is improved, but saturation occurs in bright regions
Solution Approach 1:
The patent divides the pixel array into regions with different exposure characteristics. Some pixels use long exposure periods to capture dark regions with high sensitivity, while other pixels use short exposure periods to avoid saturation in bright regions. This segmentation allows both dark and bright regions to be captured reliably.
Solution Approach 2:
Different pixels are assigned different exposure periods based on local image characteristics. Pixels that will capture dark regions use longer exposure periods for higher sensitivity, while pixels that will capture bright regions use shorter exposure periods to prevent saturation. This local optimization ensures reliable signal capture across varying luminance conditions.
3Measurement precision
If motion detection is performed to select signals, then accuracy is improved, but device complexity increases
Solution Approach 1:
The patent performs motion detection on a downsampled version of the image or on key regions first, before applying the motion information to select signals for all pixels. This preliminary motion detection reduces processing complexity while still providing accurate motion information for signal selection.
Solution Approach 2:
The patent uses an intermediary downsampling process or region-of-interest selection as a mediator between the raw image data and the full-motion-detection process. This intermediary step reduces the amount of data that requires complex motion analysis, thereby reducing overall processing complexity while maintaining accuracy.
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
Enables the acquisition of good HDR images even when the relative position between the object and the imaging device changes, preventing residual images and ensuring accurate pixel values by selecting the appropriate signal based on motion detection and saturation status.
Implementation Method 1
a first signal based on charge generated by the photoelectric converter in a first exposure period and a second signal based on charge generated by the photoelectric converter in a second exposure period
Data Source
AI summary
An imaging device includes a drive unit that drives pixels each including a photoelectric converter to output a first signal based on charge generated by the photoelectric converter in a first exposure period and a second signal based on charge generated by the photoelectric converter in a second exposure period shorter than the first exposure period, a detection unit that detects a change in a relative position between an object and the imaging device by using the first and second signals, and an image generation unit that generates an image by using the first and second signals. When selecting the first or second signal for each pixel, in accordance with a result of determination whether the first signal is saturated, the image generation unit decides whether or not to use a detection result from the detection unit as a criterion in selecting the first or second signal.