IMAQ Find Circles VI

LabView NI Vision

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IMAQ Find Circles VI

Owning Palette: MorphologyInstalled With: NI Vision Development Module

Separates overlapping circular particles and classifies them based on their radius, surface area, and perimeter. Starting from a binary image, it finds the radius and center of the circular particles even when multiple circular particles overlap. In addition, this VI can trace the circles in the destination image. It constructs and uses a Danielsson distance map to determine the radius of each particle.

Note This VI modifies the source image. If you need the original source image, create a copy of the image using the IMAQ Copy VI before using this VI.

IMAQ Find Circles

Image Src is a reference to the source image.

Image Dst is a reference to the destination image.

Min Radius specifies the smallest radius, in pixels, to detect. The default is 1.

error in (no error) describes the error status before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.

	status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

Max Radius specifies the largest radius, in pixels, to detect. The default is 10.

Image Dst Out is a reference to the destination image. If Image Dst is connected, Image Dst Out is the same as Image Dst. Otherwise, Image Dst Out refers to the image referenced by Image Src.

Nb Circles returns the number of detected circles in the image.

Circles Data returns an array of measurements for all detected circles. Each element in the array has a structure containing the following elements.

	Pos. X is the horizontal position, in pixels, of the center of the circle.
	Pos. Y is the vertical position, in pixels, of the center of the circle.
	Radius is the radius of the circle in pixels.
	Core Area is the surface area, in pixels, of the nucleus of the circle as defined by the Danielsson distance map.

error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.

	status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

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