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ScanSingleRidge

Header:	AVL.h
Namespace:	avl
Module:	MetrologyBasic

Locates the strongest dark or bright pixel peak along a given path.

Applications: Very fast detection of a thin structure like a wire or a scale mark.

Syntax

void avl::ScanSingleRidge
(
	const avl::Image& inImage,
	const ScanMap& inScanMap,
	const RidgeScanParams& inRidgeScanParams,
	avl::Selection::Type inRidgeSelection,
	atl::Optional<const avl::LocalBlindness&> inLocalBlindness,
	atl::Conditional<avl::Ridge1D>& outRidge,
	atl::Optional<avl::Profile&> outBrightnessProfile = atl::NIL,
	atl::Optional<avl::Profile&> outResponseProfile = atl::NIL
)

Parameters

Name	Type	Default	Description
inImage	const Image&		Input image
inScanMap	const ScanMap&		Data precomputed with CreateScanMap
inRidgeScanParams	const RidgeScanParams&	RidgeScanParams ( ProfileInterpolation: Quadratic4 SmoothingStdDev: 0.6f RidgeWidth: 5 RidgeMargin: 2 MinMagnitude: 5.0f RidgePolarity: Dark )	Parameters controlling the ridge extraction process
inRidgeSelection	Selection::Type	Selection::Best	Selection mode of the resulting ridge
inLocalBlindness	Optional<const LocalBlindness&>	NIL	Defines conditions in which weaker ridges can be detected in the vicinity of stronger ridges
outRidge	Conditional<Ridge1D>&		Found ridge
outBrightnessProfile	Optional<Profile&>	NIL	Extracted image profile
outResponseProfile	Optional<Profile&>	NIL	Profile of the ridge operator response

Optional Outputs

The computation of following outputs can be switched off by passing value atl::NIL to these parameters: outBrightnessProfile, outResponseProfile.

Description

The operation scans the image using inScanMap previously generated from a scan path and locates the strongest ridge of the given characteristics. If there is no such ridge then the outputs are set to NIL.

Hints

Adjust inRidgeScanParams.RidgeWidth to the expected thickness of the ridge (in pixels).
Define inRidgeScanParams.RidgePolarity to detect a particular ridge type, and only that type.
If no ridge is found, try decreasing inRidgeScanParams.MinMagnitude.
For difficult cases try different settings of the inRidgeScanParams.RidgeOperator parameter.

Examples

ScanSingleRidge locates the strongest ridge using a scan map representing the scan path above.

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.