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DetectRidges_AsRegion

Extracts a pixel-precise region of bright or dark thin lines.

Syntax

void avl::DetectRidges_AsRegion
(
	const avl::Image& inImage,
	atl::Optional<const avl::Region&> inRoi,
	atl::real inStdDevX,
	atl::Optional<atl::real> inStdDevY,
	atl::real inRidgeThreshold,
	atl::real inRidgeHysteresis,
	avl::Polarity::Type inPolarity,
	const int inMinBlobArea,
	avl::Region& outRidgeRegion
)

void DetectRidges_AsRegion
(
	AvlNet.Image inImage,
	AvlNet.Region inRoi,
	float inStdDevX,
	float? inStdDevY,
	float inRidgeThreshold,
	float inRidgeHysteresis,
	AvlNet.Polarity inPolarity,
	int inMinBlobArea,
	out AvlNet.Region outRidgeRegion
)

Parameters

Name	Type	Range	Default	Description
inImage	const Image&			Input image
inRoi	Optional<const Region&>		NIL	Region of interest
inStdDevX	real	0.0 -	3.0f	Smoothing standard deviation (horizontal)
inStdDevY	Optional<real>	0.0 -	NIL	Smoothing standard deviation (vertical, or Auto = horizontal)
inRidgeThreshold	real	0.0 -	5.0f	Sufficient ridge strength; ridges of that strength will always be detected
inRidgeHysteresis	real	0.0 -	4.0f	Value by which the ridge threshold is decreased for ridge points neighboring with sufficiently strong edges
inPolarity	Polarity::Type
inMinBlobArea	const int	0 -	1	Minimal area of a ridge blob
outRidgeRegion	Region&

Hints

Connect an input image to the inImage input.
Set inPolarity in accordance to which type of thin lines you want to detect.
Start with inRidgeHysteresis = 0 and set inRidgeThreshold so that each important edge is at least partially detected. Then keep increasing inRidgeHysteresis until the edges are detected completely.
If the edges are rugged or there are too many false edges, then try increasing inStdDevX.

Remarks

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