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DetectCalibrationGrid_Circles

Header:	FIL.h
Namespace:	fil

Detects an arbitrary size symmetric circle pattern on the image.

Syntax

void fil::DetectCalibrationGrid_Circles
(
	const fil::Image& inImage,
	ftl::Optional<const fil::Region&> inRoi,
	float inCircleRadius,
	float inCircleDetectionThreshold,
	fil::Polarity::Type inCirclePolarity,
	ftl::Array<fil::AnnotatedPoint2D>& outImageGrid,
	fil::Region& diagCirclesRegion,
	ftl::Array<fil::Point2D>& diagCircleCandidates
)

Parameters

Name	Type	Range	Default	Description
inImage	const Image&			Input image
inRoi	Optional<const Region&>		NIL	Range of pixels to be processed
inCircleRadius	float	1.0 -		Circle radius measured in input image pixels.
inCircleDetectionThreshold	float	0.0 -	20.0f	Detection threshold (relative to local image patch).
inCirclePolarity	Polarity::Type		Any	Circle intensity with respect to background.
outImageGrid	Array<AnnotatedPoint2D>&			Detected grid
diagCirclesRegion	Region&			Image after thresholding, this is the circle detector input.
diagCircleCandidates	Array<Point2D>&			Detected circle centers, before the grid construction step.

Hints

Circles may have holes. This can utilized, for example, for designating some specific coordinates on the calibration board. Note that the hole diameter must be less than a half of the circle diameter.

Examples

Input image for DetectCalibrationGrid_Circles executed with inCircleRadius = 5

Detected calibration points

Remarks

The circle pattern must be a rectangular grid, with equal spacing in both dimensions.

Errors

List of possible exceptions:

Error type	Description
DomainError	Region of interest exceeds an input image.