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DetectRidges_AsPaths

Extracts subpixel-precise paths that represent bright or dark thin lines.

Syntax

void avl::DetectRidges_AsPaths
(
	const avl::Image& inImage,
	atl::Optional<const avl::Region&> inRoi,
	float inStdDevX,
	atl::Optional<float> inStdDevY,
	float inRidgeThreshold,
	float inRidgeHysteresis,
	avl::Polarity::Type inPolarity,
	atl::Array<avl::Path>& outRidges
)

void DetectRidges_AsPaths
(
	Image inImage,
	Region? inRoi,
	float inStdDevX,
	float? inStdDevY,
	float inRidgeThreshold,
	float inRidgeHysteresis,
	Polarity inPolarity,
	out Path[] outRidges
)

Parameters

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

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.

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.