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Idillus

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Comments and Ratings by Idillus View all
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  • 9
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09 May 2009 Hough Transform for circle detection An optimized Hough transform for circle detection. Author: Peter Bone

Nice function. Can you tell me how to find the radious and values?
29 Apr 2009 Analytical intersection area between two circles Compute the intersection area between 2 circles. The function allows to evaluate the intersection ar Author: Guillaume JACQUENOT
15 Apr 2009 Contrast Limited Adaptive Histogram Equalization (CLAHE) Best to read the reference in "Graphics Gems IV", Academic Press, 1994 pages 474-485 Author: Leslie Smith
06 Apr 2009 Detects multiple disks (coins) in an image using Hough Transform HOUGHCIRCLES detects multiple disks (coins) in an image using Hough Transform. Author: Yuan-Liang Tang

Sorry, I've made ma mistake

if (nargin >=3 || nargin <= 6)
    
    if nargin==3
        thresh = 0.33; % One third of the perimeter
        delta = 12; % Each element in (x y r) may deviate approx. 4 pixels
        edgeim = edge(im, 'canny', [0.15 0.2]);
    end
    
    if nargin==4
        edgeim = edge(im, 'canny', [0.15 0.2]);
        delta = 12;
    end
    
    if (nargin==5)
        edgeim = edge(im, 'canny', canny_th);
        delta = 12;
    end
    
    if (nargin==6)
       edgeim = edge(im, 'canny', canny_th,sigma);
       delta=12;
    end
    if (nargin == 7)
         edgeim = edge(im, 'canny', canny_th,sigma);
    end
end

if minR<0 || maxR<0 || minR>maxR || thresh<0 || thresh>1 || delta<0 || canny_th <0 || canny_th >1
  disp('Input conditions: 0<minR, 0<maxR, minR<=maxR, 0<thresh<=1, 0<delta');
  return;
end
06 Apr 2009 Detects multiple disks (coins) in an image using Hough Transform HOUGHCIRCLES detects multiple disks (coins) in an image using Hough Transform. Author: Yuan-Liang Tang

Hi, nice function. I've made some changes that may be interesting. It wold be nice to change the threshold and sigma value for canny edge detection, so, I added a few lines to improve this, changing the location of the definition of the edgeimage

if nargin==3
    
    thresh = 0.33; % One third of the perimeter
    delta = 12; % Each element in (x y r) may deviate approx. 4 pixels
    edgeim = edge(im, 'canny', [0.15 0.2]);

elseif nargin==4

    if ((max(size(canny_th) == 2)) || (max(size(canny_th) == 1)))
        if max(size(canny_th) == 2)
            edgeim = edge(im, 'canny', [canny_th(1) canny_th(2)]);
        end
        if max(size(canny_th) == 1)
            edgeim = edge(im, 'canny', canny_th(1));
        end
    end
    delta = 12;
    
else (nargin==5)

    if ((max(size(canny_th) == 2)) || (max(size(canny_th) == 1)))
        if (max(size(canny_th) == 2))
            edgeim = edge(im, 'canny', [canny_th(1) canny_th(2)],sigma);
        end
        if (max(size(canny_th) == 1))
            edgeim = edge(im, 'canny', canny_th(1),sigma);
        end
    end
    delta = 12;
end

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