gistfile1.py

# this uses openvc's hough circles detection to find circles in the image
# http://docs.opencv.org/modules/imgproc/doc/feature_detection.html?highlight=cvhoughcircles#houghcircles
circles = cvHoughCircles(thresholded, storage, CV_HOUGH_GRADIENT, 2, thresholded.height/4, 100, 40, 20, 200)

# find largest circle
maxRadius = 0
x = 0
y = 0
found = False
for i in range(circles.total):
    circle = circles[i]
if circle[2] > maxRadius:
    found = True
    maxRadius = circle[2]
    x = circle[0]
    y = circle[1]