Dynamic Mask Illumination for Halation Control in Image Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image measurement systems face challenges in accurately capturing images of objects with varying surface reflectance due to local halation effects, which can lead to partial whiteout and reduced dynamic range in captured images.
Innovation Solution
The system employs a projector to emit illumination light with a dynamically adjustable radiation pattern, allowing for the setting of mask areas with reduced illumination to mitigate halation, enabling the acquisition of image information from high-reflectance and low-reflectance areas by adjusting the projection pattern accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If uniform illumination light is emitted to the entire field of view, then the image measurement accuracy is improved for low-reflectance areas, but local halation occurs in high-reflectance areas causing partial whiteout
Solution Approach 1:
The patent applies local quality by dividing the illumination field into multiple regions with different illumination intensities. Specifically, the field of view is divided into a first region (high-reflectance area) and a second region (low-reflectance area), with different illumination light quantities emitted to each region. This resolves the contradiction by providing strong illumination to low-reflectance areas for accurate measurement while reducing illumination to high-reflectance areas to prevent local halation and partial whiteout.
Solution Approach 2:
The patent segments the illumination control into multiple independent regions. The controller separately controls the illumination light quantity for the first region and the second region, allowing independent optimization of illumination parameters for each region. This segmentation enables the system to address different measurement challenges in different areas simultaneously, improving overall measurement accuracy while preventing halation artifacts.
2Object-affected harmful factors
If the illumination light quantity is reduced in high-reflectance areas to prevent halation, then local halation is suppressed, but the dynamic range of the captured image is reduced
Solution Approach 1:
The patent restores dynamic range by applying local quality enhancement to the first region (high-reflectance area). The image processing unit specifically enhances the dynamic range of the first region based on the correspondence between the first and second regions. This allows the system to maintain halation suppression through reduced illumination while compensating for the dynamic range reduction through selective image processing enhancement in the high-reflectance area.
3Object-affected harmful factors
If mask areas are introduced to control illumination distribution, then halation is reduced in high-reflectance areas, but the device complexity increases
Solution Approach 1:
The patent implements dynamic mask area control where the positions and sizes of mask areas are not fixed but can be adjusted based on the specific measurement requirements and object characteristics. The controller dynamically determines the illumination light quantity distribution and mask area configurations for each measurement task, allowing the system to adapt to different measurement scenarios without requiring complex hardware modifications for each case.
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 improves the dynamic range of imaging by allowing for appropriate image acquisition across objects with varying surface reflectance, effectively reducing halation and enhancing image information retrieval.
Implementation Method 1
a projector (6) that emits illumination light (61) in accordance with a radiation pattern
Implementation Method 2
an imaging unit (4) that captures an image of the object and outputs an image signal
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An image measurement system includes a controller (100), a projector (6) for emitting illumination light in accordance with a radiation pattern specified from the controller, an imaging unit (4) having a field of view in which an area irradiated with illumination light exists, and a display unit (120) adapted to display an image. The controller includes display control means for displaying on a display unit an image of the field of view captured by the imaging unit in a state in which illumination light is emitted, receiving means for receiving a setting of a mask area in association with the image displayed on the display unit, the mask area being an area in which the quantity of illumination light should be reduced compared with another area in the field of view, and updating means for updating the radiation pattern in accordance with the set mask area, based on a correspondence in position between the radiation pattern of the projector and a projection pattern produced in the field of view by the radiation pattern.