You are here: Start » Filter Reference » 1D Edge Detection » ScanSingleRidge
Locates the strongest dark or bright pixel peak along a given path.
Name | Type | Range | Description | |
---|---|---|---|---|
![]() |
inImage | Image | Input image | |
![]() |
inScanPath | Path | Path along which the scan is performed | |
![]() |
inScanPathAlignment | CoordinateSystem2D* | Adjusts the scan path to the position of the inspected object | |
![]() |
inScanWidth | Integer | 1 - ![]() |
Width of the scan field in pixels |
![]() |
inImageInterpolation | InterpolationMethod | Interpolation method used in extraction of image pixel values | |
![]() |
inRidgeScanParams | RidgeScanParams | Parameters controlling the ridge extraction process | |
![]() |
inRidgeSelection | Selection | Selection mode of the resulting ridge | |
![]() |
inLocalBlindness | LocalBlindness* | Defines conditions in which weaker edges can be detected in the vicinity of stronger edges | |
![]() |
outRidge | Ridge1D? | Found ridge | |
![]() |
outAlignedScanPath | Path | Path along which the scan is performed; in the image coordinate system | |
![]() |
diagBrightnessProfile | Profile | Extracted image profile | |
![]() |
diagResponseProfile | Profile | Profile of the ridge operator response | |
![]() |
diagSamplingPoints | PathArray | Array of paths each one containing the sampling points that contributed to a single value of the extracted profile | |
![]() |
diagSamplingStep | Real | Used distance between consecutive sampling points on the scan path |
Applications
Description
The operation scans the image along inScanPath and locates the strongest ridge of the given characteristics. If there is no such ridge then the outputs are set to NIL.
The optional parameter inScanPathAlignment defines a transform to be performed on the inScanPath so that the actual scan path (outAlignedScanPath) is adjusted to the position of the object, typically detected by one of Template Matching filters.
Hints
- Connect an input image to the inImage input.
- Create inScanPath which is more or less perpendicular to the ridges you want to detect. It should be long enough to anticipate all possible ridge locations.
- Adjust inRidgeScanParams.RidgeWidth to the expected thickness of the ridge (in pixels).
- Define inRidgeScanParams.RidgePolarity to detect a particular ridge type, and only that type.
- Use a local coordinate system connected to inScanPathAlignment to automatically adjust the measurement to variable object position (optional).
- If the noise level is high, try increasing inScanWidth and/or inRidgeScanParams.SmoothingStdDev.
- If no ridge is found, try decreasing inRidgeScanParams.MinMagnitude.
- For difficult cases try different settings of the inRidgeScanParams.RidgeOperator parameter.
Examples

ScanSingleRidge locates the strongest ridge across inScanPath.
Remarks
For more information about local coordinate systems please refer to the following article.
This filter is a part of the 1D Edge Detection toolset. For a comprehensive introduction to this technique please refer to 1D Edge Detection and 1D Edge Detection - Subpixel Precision chapters of our Machine Vision Guide.
Complexity Level
This filter is available on Basic Complexity Level.
Filter Group
This filter is member of ScanRidges filter group.
See Also
- ScanExactlyNRidges – Locates a specified number of the strongest dark or bright pixel peak along a given path.
- ScanMultipleRidges – Locates multiple dark or bright pixel peaks along a given path.