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AVL.ScanMultipleEdges3D_Direct

Locates multiple changes of surface height along a given path.

Namespace:AvlNet
Assembly:AVL.NET.dll

Syntax

C++
C#
 
public static void ScanMultipleEdges3D_Direct
(
	AvlNet.Surface inSurface,
	AvlNet.Path inScanPath,
	int inScanWidth,
	AvlNet.InterpolationMethod inSurfaceInterpolation,
	AvlNet.EdgeScanParams3D inEdgeScanParams,
	float inMinDistance,
	IList<AvlNet.SurfaceEdge1D> outEdges
)

Parameters

Name Type Range Default Description
inSurfaceAvlNet.SurfaceInput surface.
inScanPathAvlNet.PathPath along which the scan is performed.
inScanWidthint<1, INF>5Width of the scan field in pixels. Default value: 5.
inSurfaceInterpolationAvlNet.InterpolationMethodBilinearInterpolation method used for extraction of surface points. Default value: Bilinear.
inEdgeScanParamsAvlNet.EdgeScanParams3DEdgeScanParams3D ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 0.6f MinMagnitude: 5.0f EdgeTransition: LowToHigh )Parameters controlling the surface edge extraction process. Default value: EdgeScanParams3D ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 0.6f MinMagnitude: 5.0f EdgeTransition: LowToHigh ).
inMinDistancefloat<0.0f, INF>0.0fMinimal distance between consecutive edges. Default value: 0.0f.
outEdgesSystem.Collections.Generic.IList<AvlNet.SurfaceEdge1D>Found surface edges.

Description

The operation scans the surface along inScanPath and detects surface edges perpendicular to the path. Depending on the inEdgeScanParams.edgeTransition parameter, edges representing increase or decrease (or both) of surface height along the path will be taken into account.

When the number of edges to be found is known, one can use the ScanExactlyNEdges3D.

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.

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).

The operation is very similar to ScanMultipleEdges from 1DEdgeDetection category, but there are some substantial differences. One of these is the possibility of absence of information, because some surface points may not exist at all. To detect such edges, where solely change of existence matters, Valid/Invalid options of inEdgeScanParams.EdgeTransition can be used. Outside the surface domain (i.e. rectangle defined by input surface width, height, offsets and scales) there are no valid or invalid points, so no edge can be found in the direct vicinity of the domain border.

Please note that when the input surface has unequal scales along X and Y axes and the scan path is not parallel to any of the axes, the results may be slightly less accurate because of uneven sampling along axes.

Remarks

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

Function Overrides

See also