Profile Extraction Process
Profile extraction involves extracting a profile from the raw image. Parameters in the Profile Extraction category influence both the process and result of profile extraction. Understanding the profile extraction process helps in adjusting these parameters.
Examples
This topic uses the following raw images as examples.
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Left: Contains one laser line, simulating a simple scenario of reflection on the surface of the target object. A profile needs to be extracted from a proper position.
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Right: Contains multiple laser lines, simulating a complex scenario of reflection on the surface of the target object. In such scenarios, the raw images tend to contain unnecessary laser lines that are excessively dark, broad, or narrow, caused by situations such as interreflection. A profile needs to be extracted from proper laser lines despite the presence of unusable laser lines.
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Profile Extraction Process
The steps to extract a profile are as follows:
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Valid pixels identification: Pixels in the raw image with grayscale values greater than Min Grayscale Value are considered valid. Pixels with grayscale values smaller than that are considered invalid and do not participate in profile extraction.
When the Exposure information toggle switch is turned on, invalid pixels are displayed in light blue. Other pixels are valid. The images below demonstrate the visual effect:
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Edge selection: Select the location for extracting the profile in each laser line based on the value of Edge Selection.
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Blue line: Top edge
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Green line: Center
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Red line: Bottom
Images in the following steps display the effect after Center is selected.
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Candidate extraction spots calculation: The raw image may contain multiple laser lines. After identifying valid spots and selecting the edge, candidate extraction spots in each column of pixels will be calculated (the green spots in the image below).
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Candidate extraction spots filtering: Filter candidate extraction spots based on the values of Min Laser Line Width, Max Laser Line Width, and Min Sharpness to identify pixels that meet the requirements.
Filtering result when the parameters above are set to appropriate values:
Filtering result when the values of the parameters above are set according to the brightest laser line in the center:
Inappropriate parameter values may lead to the failure in extracting some profiles. For example, when the value of Min Laser Line Width is too large, the straight laser line in the left image may be screened out, resulting in missing parts of the profile.
In the scenario of the image to the left that contains only one laser line, the profile extraction is finished . The candidate extraction spots remained in this step (the blue spots in the raw image) are the final extraction spots.
In the scenario of the image to the right that contains multiple laser lines, some columns of the pixels may still contain more than one candidate extraction spot after the previous steps. The final extraction spots need to be identified based on the value of Spot Selection. The images below demonstrate the extraction results when the parameter value is set to Strongest and Farthest:
Strongest |
Farthest |
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