Composite Image Luminance Optimization for Dynamic Range Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the FA field, visual sensors face challenges in accurately capturing images of measuring objects due to limited dynamic range of image pickup elements, leading to overexposure or underexposure issues, especially with objects having varying reflectance and irregular surfaces, which hinders proper inspection and measurement.
Innovation Solution
An image processing apparatus that photographs a measuring object multiple times under different exposure conditions, calculates standardized luminance, and compiles image data to generate composite images with increased gradation numbers, optimizing luminance for specific areas and converting luminance to ensure accurate representation without saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the exposure amount is increased to capture dark areas, then the luminance information of dark areas is improved, but overexposure occurs in bright areas causing loss of luminance information
Solution Approach 1:
The patent divides the image processing into multiple exposure segments, capturing the same scene at different exposure levels. Each exposure captures different luminance ranges, and these segments are later combined to create a composite image that preserves luminance information across the entire dynamic range without overexposure or underexposure in any region.
Solution Approach 2:
The patent changes the exposure parameter across multiple captures, taking images with varying exposure amounts (underexposed, properly exposed, overexposed). By systematically varying this parameter and then merging the results with appropriate weighting, the system recovers luminance information that would be lost in any single exposure.
2Measurement precision
If the exposure amount is decreased to prevent overexposure, then the luminance information of bright areas is preserved, but underexposure occurs in dark areas causing loss of luminance information
Solution Approach 1:
The patent segments the capture process into multiple exposures with different luminance characteristics. The underexposed images capture dark area details while preventing bright area overexposure, and these segments are combined with properly exposed and overexposed segments to ensure all luminance information is preserved in the final composite.
Solution Approach 2:
The patent systematically varies the exposure parameter across multiple captures, including deliberately underexposed shots. By changing this parameter and then merging results with appropriate weighting functions, the system recovers dark area luminance information that would be lost in a single properly exposed image.
3Measurement precision
If multiple photographing conditions are used to extend dynamic range, then the luminance range is improved, but the processing complexity increases
Solution Approach 1:
The patent applies local quality by using different weighting functions for different luminance regions. The weighting function assigns higher weights to appropriately exposed regions and lower weights to overexposed or underexposed regions on a pixel-by-pixel basis, allowing the merging process to optimally combine information from multiple exposures while accounting for local luminance characteristics.
Solution Approach 2:
The patent implements self-service through automatic weighting function application and composite image generation. The system automatically determines appropriate weights for each pixel based on the luminance characteristics and exposure conditions, eliminating the need for manual intervention and reducing processing complexity despite multiple photographing conditions.
4Measurement precision
If composition processing is performed for every area, then the luminance range is optimized globally, but the processing time increases when only specific areas need optimization
Solution Approach 1:
The patent extracts and processes only the necessary areas requiring luminance optimization. By identifying specific regions of interest that need dynamic range extension and applying composition processing selectively to these areas rather than the entire image, the system reduces processing time while maintaining optimization where needed.
Solution Approach 2:
The patent performs preliminary identification of areas requiring luminance optimization before applying the full composition processing. By pre-processing to determine which regions need dynamic range extension and preparing appropriate weighting functions in advance, the system minimizes processing time for the actual composition operation.
Data Source
AI summary
When an area desired to be displayed with high accuracy and an area desired to be inspected and measured with high accuracy in a measuring object are smaller than a photographing range, the entire area of a composite image is displayed and designation of an area is received, to thereby generate an image of the entire area in which composition processing of optimizing luminance of pixels included in this area is performed. Therefore, an input part is provided for receiving the setting of a designated area in image data, a composite luminance distribution is calculated based on the size of a standardized luminance distribution value in the designated area, and composite image data is generated.