Fix houghcircles.py when no circles found

In the C++ equivalent of this example a check is made whether the vector (here in Python we have a list) actually has any circles in it that is whether the Hough circles function has managed to find any in the given image. This check is missing for the Python example and if no circles are found the application breaks.
This commit is contained in:
Aleksandar Atanasov 2016-06-02 10:58:46 +02:00
parent 5d4f22e096
commit cf0df733da

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@ -29,10 +29,12 @@ if __name__ == '__main__':
cimg = src.copy() # numpy function
circles = cv2.HoughCircles(img, cv2.HOUGH_GRADIENT, 1, 10, np.array([]), 100, 30, 1, 30)
a, b, c = circles.shape
for i in range(b):
cv2.circle(cimg, (circles[0][i][0], circles[0][i][1]), circles[0][i][2], (0, 0, 255), 3, cv2.LINE_AA)
cv2.circle(cimg, (circles[0][i][0], circles[0][i][1]), 2, (0, 255, 0), 3, cv2.LINE_AA) # draw center of circle
if circles != 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):
cv2.circle(cimg, (circles[0][i][0], circles[0][i][1]), circles[0][i][2], (0, 0, 255), 3, cv2.LINE_AA)
cv2.circle(cimg, (circles[0][i][0], circles[0][i][1]), 2, (0, 255, 0), 3, cv2.LINE_AA) # draw center of circle
cv2.imshow("source", src)
cv2.imshow("detected circles", cimg)