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AVL.ScanExactlyNEdges_Direct

Locates a specified number of the strongest transitions between dark and bright pixels along a given path (without a scan map).

Namespace:AvlNet
Assembly:AVL.NET.dll

Syntax

C++
C#
 
public static void ScanExactlyNEdges_Direct
(
	AvlNet.Image inImage,
	AvlNet.Path inScanPath,
	AvlNet.CoordinateSystem2D? inScanPathAlignment,
	int inScanWidth,
	AvlNet.SamplingParams inSamplingParams,
	AvlNet.EdgeScanParams inEdgeScanParams,
	int inEdgeCount,
	AvlNet.Selection inEdgeSelection,
	float inMinDistance,
	float? inMaxDistance,
	AvlNet.LocalBlindness? inLocalBlindness,
	INullable<List<AvlNet.Edge1D>> outEdges,
	INullable<List<AvlNet.Gap1D>> outGaps,
	NullableRef<AvlNet.Path> outAlignedScanPath
)

Parameters

Name Type Range Default Description
inImageAvlNet.ImageInput image.
inScanPathAvlNet.PathPath along which the scan is performed.
inScanPathAlignmentAvlNet.CoordinateSystem2D?Adjusts the scan path to the position of the inspected object. Default value: atl::NIL.
inScanWidthint<1, INF>5Width of the scan field in pixels. Default value: 5.
inSamplingParamsAvlNet.SamplingParamsSamplingParams ( Interpolation: Bilinear SamplingStep: 1.0f SampleCount: Nil )Parameters controlling the sampling process. Default value: SamplingParams ( Interpolation: Bilinear SamplingStep: 1.0f SampleCount: Nil ).
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 ).
inEdgeCountint<0, INF>1Number of edges to be found. Default value: 1.
inEdgeSelectionAvlNet.SelectionSelection mode of the resulting edges.
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.
outEdgesAvlNet.INullable<System.Collections.Generic.List<AvlNet.Edge1D>>Found edges. This parameter cannot be null.
outGapsAvlNet.INullable<System.Collections.Generic.List<AvlNet.Gap1D>>Gaps between consecutive edges. This parameter cannot be null.
outAlignedScanPathAvlNet.NullableRef<AvlNet.Path>Transformed input path. Can be null to skip this parameter calculation.

Description

The operation scans the image along inScanPath and finds a set of inEdgeCount image edges perpendicular to the path. If no subset (of inEdgeCount elements) of detected edges meets the requirements of inEdgeScanParams.minMagnitude, inMinDistance, inEdgeScanParams.edgeTransition 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.

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).

Examples

ScanExactlyNEdges locates the edges across inScanPath (inEdgeCount = 61).

Remarks

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