# AVL.FitSegmentToRidges_Direct

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

Namespace: AvlNet AVL.NET.dll

### Syntax

C++
C#

public static void FitSegmentToRidges_Direct
(
AvlNet.Image inImage,
AvlNet.SegmentFittingField inFittingField,
AvlNet.CoordinateSystem2D? inFittingFieldAlignment,
int inScanCount,
int inScanWidth,
AvlNet.SamplingParams inSamplingParams,
AvlNet.RidgeScanParams inRidgeScanParams,
AvlNet.Selection inRidgeSelection,
AvlNet.LocalBlindness? inLocalBlindness,
float inMaxIncompleteness,
AvlNet.LineMEstimator? inOutlierSuppression,
out AvlNet.Segment2D? outSegment,
IList<AvlNet.Ridge1D?> outRidges,
INullable<AvlNet.Profile> outDeviationProfile,
out AvlNet.SegmentFittingField outAlignedFittingField,
IList<AvlNet.Point2D> outInliers,
IList<AvlNet.Segment2D> diagScanSegments,
IList<AvlNet.Rectangle2D> diagSamplingAreas,
IList<AvlNet.Profile> diagBrightnessProfiles,
IList<AvlNet.Profile> diagResponseProfiles
)


### Parameters

Name Type Range Default Description
inImageAvlNet.ImageImage to fit segment to.
inFittingFieldAvlNet.SegmentFittingFieldSegment fitting field.
inFittingFieldAlignmentAvlNet.CoordinateSystem2D?Adjusts the fitting field to the position of the inspected object. Default value: atl::NIL.
inScanCountint<3, INF>10The number of points that will be searched to estimate the position of the segment. Default value: 10.
inScanWidthint<1, INF>5The width of each scan field (in pixels). Default value: 5.
inSamplingParamsAvlNet.SamplingParamsParameters controlling the sampling process.
inRidgeScanParamsAvlNet.RidgeScanParamsRidgeScanParams ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 1.0f RidgeWidth: 5 RidgeMargin: 2 MinMagnitude: 5.0f RidgePolarity: Dark )Parameters controlling the ridge extraction process. Default value: RidgeScanParams ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 1.0f RidgeWidth: 5 RidgeMargin: 2 MinMagnitude: 5.0f RidgePolarity: Dark ).
inRidgeSelectionAvlNet.SelectionSelection mode of ridges.
inLocalBlindnessAvlNet.LocalBlindness?Defines conditions in which weaker ridges can be detected in the vicinity of stronger ridges. Default value: atl::NIL.
inOutlierSuppressionAvlNet.LineMEstimator?Selects a method for ignoring incorrectly detected points. Default value: atl::NIL.
outSegmentAvlNet.Segment2D?Fitted segment or nothing if the fitting fails.
outRidgesSystem.Collections.Generic.IList<AvlNet.Ridge1D?>Found ridges.
outDeviationProfileAvlNet.INullable<AvlNet.Profile>Profile of distances between the actual segment points and the corresponding reference segment points. This parameter cannot be null.
outAlignedFittingFieldAvlNet.SegmentFittingFieldFitting field used; in the image coordinate system.
diagScanSegmentsSystem.Collections.Generic.IList<AvlNet.Segment2D>Segments along which the scans were run.
diagSamplingAreasSystem.Collections.Generic.IList<AvlNet.Rectangle2D>Areas from which the input image is sampled.
diagBrightnessProfilesSystem.Collections.Generic.IList<AvlNet.Profile>Extracted image profiles.
diagResponseProfilesSystem.Collections.Generic.IList<AvlNet.Profile>Profiles of the ridge operator response.

### Description

The operation tries to fit a given segment to ridges present in the inImage image. Internally, it performs a series of scans with the ScanSingleRidge_Direct filter along inScanCount specific scan segments which length is always equal to the inFittingField width and cannot be less than 4. 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.

### Examples

Fitting a segment to a line on an object
(inRidgeScanParams.RidgePolarity = Dark).

### Remarks

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

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.

Hardware acceleration settings may be manipulated with Settings class.