hough_circle_trans — Return the Hough-Transform for circles with a given radius.
hough_circle_trans(Region : HoughImage : 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.
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.
Number of elements: 1 <= Radius <= 500
Default value: 12
Typical range of values: 3
≤
Radius
(lin)
Minimum increment: 1
Recommended increment: 1
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 is raised.
Foundation