Exposure Information, Intensity Curve, and Sharpness Curve
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 value of the Min Grayscale Value parameter in the Profile Extraction category: light yellow
The above information helps adjust Exposure Time (Timed mode) / Total exposure time in HDR Exposure Settings (HDR mode) and Min Grayscale Value.
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 to Timed: 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 average grayscale values of valid pixels in the laser lines. The intensity curve can be used to check the specific 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 your requirement after the above adjustments, 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 Min Sharpness parameter in the Profile Extraction category based on the sharpness curve:
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Place the cursor on the spot whose sharpness value you need to check, its sharpness value 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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