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DetectCalibrationGrid_Circles

Detects an arbitrary size symmetric circle pattern on the image.

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

Applications

Camera calibration, image to world coordinates transformations.

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

This filter can throw an exception to report error. Read how to deal with errors in Error Handling.

List of possible exceptions:

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

Complexity Level

This filter is available on Advanced Complexity Level.

Filter Group

This filter is member of DetectCalibrationGrid filter group.