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Locates multiple transitions between dark and bright pixels along a given path.



public static void ScanMultipleEdges
	AvlNet.Image inImage,
	AvlNet.ScanMap inScanMap,
	AvlNet.EdgeScanParams inEdgeScanParams,
	float inMinDistance,
	float? inMaxDistance,
	AvlNet.LocalBlindness? inLocalBlindness,
	IList<AvlNet.Edge1D> outEdges,
	IList<AvlNet.Gap1D> outGaps,
	NullableRef<AvlNet.Profile> outBrightnessProfile,
	NullableRef<AvlNet.Profile> outResponseProfile


Name Type Range Default Description
inImageAvlNet.ImageInput image.
inScanMapAvlNet.ScanMapData precomputed with CreateScanMap.
inEdgeScanParamsAvlNet.EdgeScanParamsEdgeScanParams ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 0.6f MinMagnitude: 5.0f EdgeTransition: BrightToDark )Parameters controlling the edge extraction process. Default value: EdgeScanParams ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 0.6f MinMagnitude: 5.0f EdgeTransition: BrightToDark ).
inMinDistancefloat<0.0f, INF>0.0fMinimal distance between consecutive edges. Default value: 0.0f.
inMaxDistancefloat?<0.0f, INF>Maximal distance between consecutive edges. Default value: atl::NIL.
inLocalBlindnessAvlNet.LocalBlindness?Defines conditions in which weaker edges can be detected in the vicinity of stronger edges. Default value: atl::NIL.
outEdgesSystem.Collections.Generic.IList<AvlNet.Edge1D>Found edges.
outGapsSystem.Collections.Generic.IList<AvlNet.Gap1D>Gaps between consecutive edges.
outBrightnessProfileAvlNet.NullableRef<AvlNet.Profile>Extracted image profile. Can be null to skip this parameter calculation.
outResponseProfileAvlNet.NullableRef<AvlNet.Profile>Profile of the edge (derivative) operator response. Can be null to skip this parameter calculation.


The operation scans the image using inScanMap previously generated from a scan path and detects image edges perpendicular to the path. Depending on the inEdgeScanParams.edgeTransition parameter, edges representing increase or decrease (or both) of image brightness along the path will be taken into account.

When the number of edges to be found is known, one can use the ScanExactlyNEdges.

Note that in case of a scan path which is closed, the parameters controlling the distances between consecutive found objects do not control the distance between the first and the last of the found objects (counting from the beginning of the scan path).


ScanExactlyNEdges locates the edges using a scan map representing the scan path above.


Read more about Local Coordinate Systems in Machine Vision Guide: Local Coordinate Systems.

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.

Function Overrides

See also