X-Git-Url: http://git.euphorik.ch/?a=blobdiff_plain;f=src%2FTests_hough%2FHTCircle.m;fp=src%2FTests_hough%2FHTCircle.m;h=3088c241de1df48146f5807f8c7691d70997ffbe;hb=0ff8fb82457bd5a858b2218ab07f69c81323537e;hp=0000000000000000000000000000000000000000;hpb=c6fe9d606eff98fc73b75f23e02a9fd436458ed0;p=master-thesis.git

diff --git a/src/Tests_hough/HTCircle.m b/src/Tests_hough/HTCircle.m
new file mode 100644
index 0000000..3088c24
--- /dev/null
+++ b/src/Tests_hough/HTCircle.m
@@ -0,0 +1,42 @@
+% Hough Transform for circles.
+% img : logical image, zeros are the circles edges
+% radius_range is a vector : [min, max]
+function [acc_votes, acc_radius] = HTCircle(img, radius_range)
+
+    [rows, columns] = size(img);
+    
+    acc_votes = zeros(rows, columns);
+    acc_radius = zeros(rows, columns);
+    
+    phi_range = linspace(0, 2 * pi, 100);
+    phi_range(end) = [];
+    
+    indexes_non_zero = find(img)';
+    s = size(img);
+    
+    for r = radius_range(1):radius_range(2)
+        acc = zeros(rows, columns);
+        for i = indexes_non_zero
+            [y, x] = ind2sub(s, i);            
+            for phi = phi_range
+                x0 = round(x - r * cos(phi));
+                y0 = round(y - r * sin(phi));
+                if x0 < columns && x0 > 0 && y0 < rows && y0 > 0
+                    acc(y0, x0) = acc(y0, x0) + 1;
+                end
+            end
+        end
+        
+        for x = 1:columns
+            for y = 1:rows
+                if acc(y, x) > acc_votes(y, x)
+                    acc_votes(y, x) = acc(y, x);
+                    acc_radius(y, x) = r;
+                end
+            end
+        end        
+    end
+    
+    acc_votes = imgaussfilt(acc_votes, 1.0);
+end
+