3D Shape Measurement Using Luminance Peak Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for measuring three-dimensional shapes using window matching techniques face limitations in achieving high accuracy due to averaging of depth measurements across predetermined window sizes, even when images of projection patterns are captured with favorable contrast.
Innovation Solution
An image processing apparatus that recalculates the matching position for each point in the projection pattern within highly accurate shape measurable areas, utilizing a first calculation unit for window matching and a second unit to determine luminance peak positions, enabling precise three-dimensional shape measurement without averaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If window matching is performed on predetermined areas with assumed uniform displacement, then calculation is simplified, but measurement precision deteriorates due to depth averaging
Solution Approach 1:
The patent divides the measurement process into two stages: first performing window matching on predetermined areas to obtain rough matching results, then segmenting the analysis by calculating luminance peak positions for each individual projection pattern point. This segmentation allows transition from area-averaged measurement to point-specific measurement, resolving the contradiction between calculation simplicity and measurement precision.
Solution Approach 2:
The patent extracts the luminance peak position information from each projection pattern point in the captured image, separate from the overall window matching result. By taking out this specific feature (luminance peak) for each point, the method obtains precise position information without being constrained by the predetermined window size and uniform displacement assumption.
2Reliability
If window matching is performed on large predetermined areas, then robustness is improved, but measurement precision deteriorates due to depth averaging across the area
Solution Approach 1:
The patent maintains the initial window matching on predetermined areas for robustness, then segments the subsequent analysis by evaluating luminance peak positions for each projection pattern point independently. This two-stage segmentation approach preserves the robustness benefits of area-based matching while eliminating the depth averaging problem through point-specific luminance peak detection.
Data Source
AI summary
An image processing apparatus can measure a three-dimensional shape of a subject with high accuracy when an image of a projection pattern is captured with a favorable contrast. The image processing apparatus includes a matching calculation unit that performs matching calculation between a projection pattern in an image being captured and an image of a projection pattern generated by a projection pattern generation unit. An image evaluation unit calculates a contrast as an evaluation standard in the captured image. A symbol position calculation unit highly accurately calculates a position of each of a group of points forming the projection pattern, for each area in the captured image determined to be a highly accurate shape measurable area based on the contrast, and thus obtains a peak luminance position. A three-dimensional shape calculation unit calculates the three-dimensional shape of the subject.