 | Find Circular Edge Controls |
Main Tab
The following controls are available on the Main tab.
| Control Name |
Description |
| Step Name |
Name to give the step. |
| Region of Interest |
The region of interest you want to use for the step. |
| Reposition Region of Interest |
When enabled, the step dynamically repositions the region of interest based on a coordinate system you built in a previous step. |
| Reference Coordinate System |
Coordinate system to which you want to link the region of interest. |
Settings Tab
The following controls are available on the Settings tab.
| Control Name |
Description |
| Direction |
Direction in which you want the search lines to look for a straight edge within the region of interest. The following options are available:
- Outside to Inside—Searches for edges from the outside edge to inside edge of the region of interest.
- Inside to Outside—Searches for edges from the inside edge to outside edge of the region of interest.
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| Edge Polarity |
Specifies the pixel intensity transitions to use to determine edges. The following options are available:
- All Edges—Finds edges characterized by dark-to-bright and bright-to-dark pixel intensity transitions.
- Dark to Bright Only—Finds only those edges characterized by dark-to-bright pixel intensity transitions along the direction of the search line.
- Bright to Dark Only—Finds only those edges characterized by bright-to-dark pixel intensity transitions along the direction of the search line.
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| Look For |
Specifies the type of edges to find in the image. The following options are available:
- First Edge—Finds only the first edge of the specified polarity along each independent search line based on the direction of the search line.
- Best Edge—Finds only the best edge of the specified polarity along each independent search line.
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| Auto Setup |
When enabled, the step locates the strongest edge in the region of interest using the specified Direction, Edge Polarity, and Look For values and returns the parameters used to find the edge. |
| Minimum Edge Strength |
Minimum difference in the intensity values between the edge and its surroundings. Only those edges whose strength is greater than this value are used in the detection process. |
| Kernel Size |
Specifies the size of the edge detection kernel. |
| Projection Width |
Specifies the number of pixels averaged perpendicular to the search direction to compute the edge profile strength at each point along the region of interest. |
| Gap |
Number of degrees between search lines in the region of interest. |
| Edge Strength Profile |
Graphical representation of the edge contrast along the search line specified by the Search Line Index. |
| Search Line Index |
Specifies the index of the search line represented in the Edge Strength Profile. |
Advanced Tab
The following controls are available on the Advanced tab.
| Control Name |
Description |
| Edge Strength Profile |
Graphical representation of the edge contrast along the search line specified by the Search Line Index. The yellow line indicates the location of the found edge. |
| Search Line Index |
Specifies the index of the search line represented in the Edge Strength Profile. |
| Edge Points Found |
Displays information about the edge points found along all the search lines in the ROI. The following information is displayed for each edge:
- Strength—Strength of the edge. Values range from 0 to 1000 with larger values indicating a stronger edge.
- STR—Signal to threshold ratio for the edge, expressed in decibels.
- TNR—Threshold to noise ratio for the edge, expressed in decibels.
- SNR—Signal to noise ratio for the edge, expressed in decibels.
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Limits Tab
The following controls are available on the Limits tab.
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Note If you calibrate the image using the Calibrate Image step, Current Radius is returned in the calibration unit you specified. Therefore, Minimum Radius and Maximum Radius must be specified in calibration units. |
| Control Name |
Description |
| Minimum Radius |
Minimum radius the detected circle can have. |
| Maximum Radius |
Maximum radius the detected circle can have. |
| Maximum Deviation |
Maximum average error between found edge points and the fitted straight circle. |
| Step Results |
Displays information about the detected circle in the image.
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Note When you calibrate the image using a Calibrate Image step, X and Y are returned in the calibration unit you specified. |
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