Revision history [back]

actually, getting the lower/upper bounds right is the hardest thing here, then it needs a few more steps:

# binarized image:
bin = cv2.inRange(hsv, lower,upper)

# contours:
im2, contours,hierarchy = cv2.findContours(bin,2,1)  # without 'im2' for opencv2.4 !!
if len(contours)>0:
    cnt = contours[0]
    (x,y,w,h) = cv2.boundingRect(cnt)
    cv2.rectangle(img, (x,y), (x+w,y+h), (255,0,0), 1)