piwall.py 文件源码

def contour_to_monitor_coords(screenCnt):
    '''Apply pyimagesearch algorithm to identify tl,tr,br,bl points from a contour'''
    # now that we have our screen contour, we need to determine
    # the top-left, top-right, bottom-right, and bottom-left
    # points so that we can later warp the image -- we'll start
    # by reshaping our contour to be our finals and initializing
    # our output rectangle in top-left, top-right, bottom-right,
    # and bottom-left order
    pts = screenCnt.reshape(4, 2)
    rect = np.zeros((4, 2), dtype = "float32")

    # the top-left point has the smallest sum whereas the
    # bottom-right has the largest sum
    s = pts.sum(axis = 1)
    rect[0] = pts[np.argmin(s)]
    rect[2] = pts[np.argmax(s)]

    # compute the difference between the points -- the top-right
    # will have the minumum difference and the bottom-left will
    # have the maximum difference
    diff = np.diff(pts, axis = 1)
    rect[1] = pts[np.argmin(diff)]
    rect[3] = pts[np.argmax(diff)]

    return rect