sonic-track.py 文件源码

def trackPoint(grayimage1, grayimage2):
    moveData = []   # initialize list of movementCenterPoints
    biggestArea = MIN_AREA
    # Get differences between the two greyed images
    differenceImage = cv2.absdiff( grayimage1, grayimage2 )
    # Blur difference image to enhance motion vectors
    differenceImage = cv2.blur( differenceImage,(BLUR_SIZE,BLUR_SIZE ))
    # Get threshold of blurred difference image based on THRESHOLD_SENSITIVITY variable
    retval, thresholdImage = cv2.threshold( differenceImage, THRESHOLD_SENSITIVITY, 255, cv2.THRESH_BINARY )
    try:
        thresholdImage, contours, hierarchy = cv2.findContours( thresholdImage, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE )
    except:
        contours, hierarchy = cv2.findContours( thresholdImage, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE )

    if contours != ():
        for c in contours:
            cArea = cv2.contourArea(c)
            if cArea > biggestArea:
                biggestArea = cArea
                ( x, y, w, h ) = cv2.boundingRect(c)
                cx = int(x + w/2)   # x center point of contour
                cy = int(y + h/2)   # y center point of contour
                moveData = [cx, cy, w, h]
    return moveData

#-----------------------------------------------------------------------------------------------