switch.py 文件源码

def drawCentroid(vid, color_area, mask, showCentroid):

    _, contour, _ = cv2.findContours( mask, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

    l=len(contour)
    area = np.zeros(l)

    # filtering contours on the basis of area rane specified globally 
    for i in range(l):
        if cv2.contourArea(contour[i])>color_area[0] and cv2.contourArea(contour[i])<color_area[1]:
            area[i] = cv2.contourArea(contour[i])
        else:
            area[i] = 0

    a = sorted( area, reverse=True) 

    # bringing contours with largest valid area to the top
    for i in range(l):
        for j in range(1):
            if area[i] == a[j]:
                swap( contour, i, j)

    if l > 0 :      
        # finding centroid using method of 'moments'
        M = cv2.moments(contour[0])
        if M['m00'] != 0:
            cx = int(M['m10']/M['m00'])
            cy = int(M['m01']/M['m00'])
            center = (cx,cy)
            if showCentroid:
                cv2.circle( vid, center, 5, (0,0,255), -1)

            return center
    else:
        # return error handling values
        return (-1,-1)

# This function helps in filtering the required colored objects from the background