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AvsFilter_FitSegmentToEdges

This is Filter Equivalent. This function may be present in generated code, but should not be used in hand-written code. CreateSegmentFittingMap and FitSegmentToEdges should be used instead.

Performs a series of 1D edge detections and finds a segment that best matches the detected points.

Syntax

void avs::AvsFilter_FitSegmentToEdges
(
	FitSegmentToEdgesState& ioState,
	const avl::Image& inImage,
	const avl::SegmentFittingField& inFittingField,
	atl::Optional<const avl::CoordinateSystem2D&> inFittingFieldAlignment,
	int inScanCount,
	int inScanWidth,
	const avl::InterpolationMethod::Type inImageInterpolation,
	const avl::EdgeScanParams& inEdgeScanParams,
	avl::Selection::Type inEdgeSelection,
	atl::Optional<const avl::LocalBlindness&> inLocalBlindness,
	float inMaxIncompleteness,
	atl::Optional<avl::MEstimator::Type> inOutlierSuppression,
	atl::Conditional<avl::Segment2D>& outSegment,
	atl::Optional<atl::Array<atl::Conditional<avl::Edge1D> >&> outEdges = atl::NIL,
	atl::Optional<atl::Conditional<avl::Profile>&> outDeviationProfile = atl::NIL,
	atl::Optional<avl::SegmentFittingField&> outAlignedFittingField = atl::NIL,
	atl::Array<avl::Segment2D>& diagScanSegments,
	atl::Array<avl::Rectangle2D>& diagSamplingAreas,
	atl::Array<avl::Profile>& diagBrightnessProfiles,
	atl::Array<avl::Profile>& diagResponseProfiles
)

Parameters

Name	Type	Range	Default	Description
ioState	FitSegmentToEdgesState&			Object used to maintain state of the function.
inImage	const Image&			Image to fit segment to
inFittingField	const SegmentFittingField&			Segment fitting field
inFittingFieldAlignment	Optional<const CoordinateSystem2D&>		NIL	Adjusts the fitting field to the position of the inspected object
inScanCount	int	3 -	10	The number of points that will be searched to estimate the position of the segment
inScanWidth	int	1 -	5	The width of each scan field (in pixels)
inImageInterpolation	const InterpolationMethod::Type		Bilinear	Interpolation method used for extraction of image pixel values
inEdgeScanParams	const EdgeScanParams&		EdgeScanParams ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 1.0f MinMagnitude: 5.0f EdgeTransition: BrightToDark )	Parameters controlling the edge extraction process
inEdgeSelection	Selection::Type			Selection mode of edges
inLocalBlindness	Optional<const LocalBlindness&>		NIL	Defines conditions in which weaker edges can be detected in the vicinity of stronger edges
inMaxIncompleteness	float	0.0 - 0.999	0.1f	Maximal fraction of edge points not found
inOutlierSuppression	Optional<MEstimator::Type>		NIL	Selects a method for ignoring incorrectly detected points
outSegment	Conditional<Segment2D>&			Fitted segment or nothing if the fitting fails
outEdges	Optional<Array<Conditional<Edge1D> >&>		NIL	Found edges
outDeviationProfile	Optional<Conditional<Profile>&>		NIL	Profile of distances between the actual segment points and the corresponding reference segment points
outAlignedFittingField	Optional<SegmentFittingField&>		NIL	Fitting field used; in the image coordinate system
diagScanSegments	Array<Segment2D>&			Segments along which the scans were run
diagSamplingAreas	Array<Rectangle2D>&			Areas from which the input image is sampled
diagBrightnessProfiles	Array<Profile>&			Extracted image profiles
diagResponseProfiles	Array<Profile>&			Profiles of the edge (derivative) operator response

Description

The operation tries to fit a given segment to edges present in the inImage image. Internally, it performs a series of scans with the ScanSingleEdge filter along inScanCount specific scan segments which length is always equal to the inFittingField width. The found points are then used to determine the actual position of the segment in the image. Only inMaxIncompleteness fraction of these scans may fail. If the fitting according to the given parameters is not possible, outSegment is set to Nil.

Hints

Connect an input image to the inImage input.
Define inEdgeScanParams.EdgeTransition to detect a particular edge type, and only that type.
If no or too few edge points are found, try decreasing inEdgeScanParams.MinMagnitude.
If some of the scans may fail, set the inMaxIncompleteness input accordingly.
If some of the scans may produce false results, try different values of the inOutlierSuppression input.
Use the outEdges outputs to visualize the scanning results.

Examples

Fitting two segments to the edges of a blister
(inEdgeScanParams.EdgeTransition = DarkToBright, inEdgeScanParams.SmoothingStdDev = 1.0).

Remarks

For more information about local coordinate systems please refer to the following article.

This filter is a part of the Shape Fitting toolset. To read more about this technique, one can refer to the Shape Fitting chapter of our Machine Vision Guide

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.