optical_flow_double.py 文件源码

def draw_arrow(x0, y0, x1, y1, input_img, color):

    #x0 = start_point[0]
    #y0 = start_point[1]

    #x1 = x0 + velocity[0]
    #y1 = y0 + velocity[1]

    input_img = draw_line(x0, y0, x1, y1, input_img, color)

    dx = x1 - x0
    dy = y1 - y0

    #endpoint for one edge of arrow
    x2 = x0 + 0.75 * dx + 0.25 * (3 ** -0.5) * dy
    y2 = y0 + 0.75 * dy - 0.25 * (3 ** -0.5) * dx

    x3 = x0 + 0.75 * dx - 0.25 * (3 ** -0.5) * dy
    y3 = y0 + 0.75 * dy + 0.25 * (3 ** -0.5) * dx

    input_img = draw_line(x2, y2, x1, y1, input_img, color)
    input_img = draw_line(x3, y3, x1, y1, input_img, color)

    return input_img

#transform(TypeSpecialize(checks=False))