initial commit

samples/python/houghcircles.py

@@ -0,0 +1,48 @@
+#!/usr/bin/python
+
+'''
+This example illustrates how to use cv.HoughCircles() function.
+
+Usage:
+    houghcircles.py [<image_name>]
+    image argument defaults to board.jpg
+'''
+
+# Python 2/3 compatibility
+from __future__ import print_function
+
+import numpy as np
+import cv2 as cv
+
+import sys
+
+def main():
+    try:
+        fn = sys.argv[1]
+    except IndexError:
+        fn = 'board.jpg'
+
+    src = cv.imread(cv.samples.findFile(fn))
+    img = cv.cvtColor(src, cv.COLOR_BGR2GRAY)
+    img = cv.medianBlur(img, 5)
+    cimg = src.copy() # numpy function
+
+    circles = cv.HoughCircles(img, cv.HOUGH_GRADIENT, 1, 10, np.array([]), 100, 30, 1, 30)
+
+    if circles is not None: # Check if circles have been found and only then iterate over these and add them to the image
+        _a, b, _c = circles.shape
+        for i in range(b):
+            cv.circle(cimg, (circles[0][i][0], circles[0][i][1]), circles[0][i][2], (0, 0, 255), 3, cv.LINE_AA)
+            cv.circle(cimg, (circles[0][i][0], circles[0][i][1]), 2, (0, 255, 0), 3, cv.LINE_AA)  # draw center of circle
+
+        cv.imshow("detected circles", cimg)
+
+    cv.imshow("source", src)
+    cv.waitKey(0)
+    print('Done')
+
+
+if __name__ == '__main__':
+    print(__doc__)
+    main()
+    cv.destroyAllWindows()