houghcirclescv

Detect circles in a grayscale image using the Hough transformation algorithm.

Syntax

houghcirclescv(handle, ratio, dist...)

houghcirclescv(handle, ratio, dist, param1, param2, min, max)

Inputs

handle: Handle of an image from the ComputerVision library.; Type: integer
ratio: Inverse ratio of the accumulator resolution to the image resolution.; Type: scalar
dist: Minimum distance between the centers of the detected circles.; Type: scalar
param1: Optional first method-specific parameter, defaults to 100.; Type: scalar
param2: Optional second method-specific parameter, defaults to 100.; Type: scalar
min: Optional minimum circle radius, defaults to 0.; Type: integer
max: Optional maximum circle radius, defaults to 0.; Type: integer

Example

Detect and show circles in an image using Hough transform:

src = imreadcv('bird3.jpg');
srcsize = imsizecv(src);
houghcirclescv(src, 1, srcsize(1)/16, 150,  20, 10, 30);

Detect and show circles:

%Read image
img = imreadcv('houghcirclescv_fig3.png',1);
figure(1);
imshowcv(img);
  
%Apply Hough transform on the image
houghcirclescv(img,3,2,200,300,10);

figure(2);
imshowcv(img);