hough_circle_trans ( Region : HoughImage : Radius : )

Return the Hough-Transform for circles with a given radius.

The operator hough_circle_trans calculates the Hough transform for circles with a certain Radius in the regions passed by Region. Hereby the centres of all possible circles in the parameter space (the Hough or accumulator space respectively) will be accumulated for each point in the image space. Circle hypotheses supported by many points in the input region thereby generate a maximum in the area showing the circle's centre in the output image (HoughImage). The circles' centres in the image space can be deduced from the coordinates of these maximums by subtracting the Radius. If more than one radius is transmitted, all Hough images will be shifted according to the maximal radius.


Parameters

Region (input_object)
region -> object
Binary edge image in which the circles are to be detected.

HoughImage (output_object)
image(-array) -> object : int2
Hough transform for circles with a given radius.
Number of elements: HoughImage == Radius

Radius (input_control)
integer(-array) -> integer
Radius of the circle to be searched in the image.
Default value: 12
Typical range of values: 3 <= Radius
Minimum increment: 1
Recommended increment: 1
Number of elements: (1 <= Radius) <= 500


Result

The operator hough_circle_trans returns the value 2 (H_MSG_TRUE) if the input is not empty. The behavior in case of empty input (no input regions available) is set via the operator set_system('no_object_result',<Result>), the behavior in case of empty region is set via set_system('empty_region_result',<Result>). If necessary an exception handling is raised.


Parallelization Information

hough_circle_trans is reentrant and processed without parallelization.


Module

Foundation



Copyright © 1996-2008 MVTec Software GmbH