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DetectSingleCircle

Header:	AVL.h
Namespace:	avl
Module:	FoundationBasic

Finds the strongest circle of a given radius in the input image.

Applications: Detection of a circular or close-to-circular object like a hole, pin, pill or particle.

Syntax

void avl::DetectSingleCircle
(
	const avl::Image& inImage,
	atl::Optional<const avl::Region&> inRoi,
	float inRadius,
	float inMinScore,
	float inEdgeThreshold,
	atl::Conditional<avl::HoughCircle>& outCircle,
	avl::Image& diagGradientMagnitudeImage,
	avl::Image& diagScoreImage
)

Parameters

Name	Type	Range	Default	Description
inImage	const Image&			Input image
inRoi	Optional<const Region&>		NIL	Input region of interest
inRadius	float	0.0 -	10.0f	Circle's radius
inMinScore	float	0.0 -	20.0f	Minimum matching score
inEdgeThreshold	float		10.0f	Minimum accepted edge magnitude
outCircle	Conditional<HoughCircle>&			Found circle
diagGradientMagnitudeImage	Image&			Visualized gradients magnitude of an input image
diagScoreImage	Image&			Calculated score for each pixel of an input image

Description

The operation detects circular object of given radius (in pixels) in the inImage using the Hough Transform approach.

Hints

Pass an input image to the inImage input.
Define the expected circle radius on the inRadius input.
Set inEdgeThreshold to define the minimum strength of edges that will be taken into account. Verify this value with the diagGradientMagnitudeImage output.
Experimentally set the inMinScore value, whose meaning is more or less "the number of pixels voting for a particular object location".

Examples

DetectSingleCircle performed on the sample image.

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.