Profile Extraction Aid
This section introduces the information in the Mech-Eye Viewer that can assist you in adjusting the parameters of profile extraction. The information supported varies for different product families. Please read the corresponding sections according to the device model in use.
LNX-7000 Series
In the raw image display area, you can enable the display of profile point, missing profile point, exposure information, and imaging characteristic curves. This topic introduces the methods and examples of using the exposure information, intensity curve, and sharpness curve to help adjust parameters.
Profile points and missing profile points
Once display is enabled, you can visualize the extracted profile points and unextracted points in the raw image:
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Profile point: green
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Missing profile points: yellow
Based on the displayed results, you can quickly determine the extraction integrity under the current parameter settings.
Exposure Information
After the Exposure information toggle switch is turned on, pixels with different grayscale values are displayed in different colors:
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Pixels with grayscale values equal to 255: red
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Pixels with grayscale values smaller than 3: blue
Using the above information, you can more easily adjust the exposure time (Timed Exposure and Dual Frame HDR Mode) / HDR Exposure Settings, and Intensity Threshold parameters.
Imaging Characteristic Curve
The imaging characteristic curve is used to display the intensity, sharpness, width, and effective width of the profile, which helps adjust parameters related to profile extraction.
① Intensity curve
Intensity is calculated based on the grayscale values of valid pixels in the laser lines. The intensity curve reflects the fluctuation of intensity values. It can be used to check the intensity values of each profile point and help adjust the intensity threshold parameter.
Place the cursor on the intensity curve to view the intensity values of the corresponding profile points. If you need to exclude low-intensity profile points, increase Intensity Threshold.
② Sharpness curve
Sharpness is the clearness of the edges of a laser line. Sharpness curves can be used to check the sharpness values of each profile point and help adjust the Sharpness Threshold parameter.
Place the cursor on the sharpness curve to view the sharpness values of the corresponding profile points. If you need to remove profile points whose edges are blurry, you can increase the Sharpness Threshold parameter.
③ Valid Width Curve
The valid width curve reflects the number of valid pixels in the pixel column involved in profile extraction. This curve facilitates adjusting the parameters Min Effective Width and Max Effective Width.
The following pixel columns are not involved in profile extraction:
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Columns of pixels whose valid number of pixels is smaller than the Min Valid Width parameter.
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Columns of pixels whose valid pixel count is greater than the Max valid width parameter.
④ Halo Width Curve
The Halo Width Curve displays the halo width in the pixel column where the spot is located. It helps adjust the Halo Filtering parameter.
LNX-7500/LNX-8000 Series
In the raw image display area, you can turn on the display of Exposure information and Intensity and sharpness curves. This topic introduces the methods and examples of using the exposure information, intensity curve, and sharpness curve to help adjust parameters.
Exposure Information
After the Exposure information toggle switch is turned on, pixels with different grayscale values are displayed in different colors:
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Pixels with grayscale values equal to 255: red
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Pixels with grayscale values smaller than the Min Grayscale Value parameter value in the Profile Extraction category: light yellow
Using the above information, you can more easily adjust the Exposure Time/HDR Exposure Settings, Total Exposure Time (HDR Exposure Mode), and Min Grayscale Value parameters.
Pixels Displayed in Red
Generally, when the laser line has 1 to 2 rows of pixels displayed in red (with grayscale values of 255) at the center, the brightness of the raw image is appropriate.
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If too many pixels are displayed in red, decrease Exposure Time / Total exposure time.
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If too few pixels are displayed in red, increase Exposure Time / Total exposure time.
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If some laser lines have too many pixels displayed in red, while other laser lines have too few pixels are displayed in red or even do not have spots extracted:
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When Exposure Mode is set toTimed : Try switching to HDR.
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When Exposure Mode is set to HDR: Try adjusting Expected proportions to increase the proportion of Exposure time 1 and decrease the proportion of Exposure time 3.
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Pixels Displayed in Light Yellow
Pixels displayed in light yellow (with grayscale values smaller than Min Grayscale Value) do not participate in profile extraction. If the pixels at the features to be extracted are displayed in light yellow, you can decrease Min Grayscale Value, or increase Exposure time / Total exposure time to increase the grayscale values of these pixels.
Intensity Curve
After you turn on the Intensity and sharpness curves toggle switch, the intensity curve and sharpness curve of the profile are displayed below the raw image.
Intensity is calculated based on the grayscale values of valid pixels in the laser lines. The intensity curve can be used to check the intensity value of each spot in the profile and the fluctuation in intensity values, helping adjust the parameters in the Brightness Settings category.
Check Spot Intensity Value
If you have specific requirements on intensity values, you can check the specific intensity value of each spot in the profile through the intensity curve.
Place the cursor on the raw image or intensity curve, and the intensity value of the spot of the pixel column where the cursor is located will be displayed.
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If the intensity value is too low:
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When Exposure Mode is set to Timed: You can increase Exposure Time.
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When Exposure Mode is set to HDR:
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If the overall intensity is too low, you can increase Total exposure time.
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If the intensity of the region least likely to overexpose is too low, you can increase the proportion of Exposure time 1.
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If the intensity of the region most likely to overexpose is too low, you can increase the proportion of Exposure time 3.
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If the intensity value still does not meet the requirements after adjustment, you can increase Analog Gain. -
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If the intensity value is too high:
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When Exposure Mode is set to Timed: You can decrease Exposure Time.
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When Exposure Mode is set to HDR:
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If the overall intensity is too high, you can decrease Total exposure time.
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If the intensity of the region least likely to overexpose is too high, you can decrease the proportion of Exposure time 1.
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If the intensity of the region most likely to overexpose is too high, you can decrease the proportion of Exposure time 3.
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Check Fluctuation in Intensity Values
If you have specific requirements on the fluctuation range of intensity values, you can check the fluctuation in intensity values through the intensity curve.
When checking the fluctuation in intensity values, make sure that the target object stays still relative to the laser profiler, and select a flat area with a uniform texture to check the intensity values.
If the intensity values fluctuate greatly:
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When Exposure Mode is set to Timed: Try switching to HDR.
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When Exposure Mode is set to HDR: Large fluctuation in the intensity value can be caused by Total exposure time being too short or too long.
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If the intensity of the region least likely to overexpose is too low, try increasing Total exposure time.
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If the intensity of the region least likely to overexpose is too high,try decreasing Total exposure time.
After adjusting Total exposure time, make sure to check if Expected proportions is still suitable. You can refer to the instructions in Check Spot Intensity Value. -
Sharpness Curve
After you turn on the Intensity and sharpness curves toggle switch, the intensity curve and sharpness curve of the profile are displayed below the raw image.
Sharpness is the clearness of the edges of a laser line. You can adjust the Profile Extraction category according to the sharpness curve of the Min Sharpness parameter:
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Place the cursor on the laser line, the sharpness value of the pixel column will be displayed on the sharpness curve.
If the sharpness value is low, then the laser line edge at this position is blurry; if the sharpness value is high, the laser line edge at this position is clear.
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Adjust Min Sharpness according to the sharpness value:
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If the laser line that needs to be removed has sharpness values greater than Min Sharpness, increase Min Sharpness until it is greater than the sharpness values of that laser line.
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If a laser line needed for profile extraction does not have spots displayed, the sharpness values of this laser line may be smaller than Min Sharpness. You can decrease Min Sharpness and acquire data again to see if the profile has been extracted from this laser line.
If the profile of this laser line is still not extracted after Min Sharpness has been adjusted, then the other parameters in the Profile Extraction category may have caused the laser line to be excluded.
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