optical_flow_double.py 文件源码

def find_color_value(dist, r):

    #dist is a 2D vector with magnitude smaller than 1, r is its manitude 
    #representing a position inside the color wheel

    angle = np.arctan2(dist[0], dist[1])
    color = np.array([0.0, 0.0, 0.0])

    if angle >= 0 and angle <= 2.0 * np.pi / 3.0:

        scale = angle * 3.0 / (2.0 * np.pi)
        color[0] = 1.0 - scale
        color[1] = scale

    if angle > 2.0 * np.pi / 3.0:

        scale = (angle - 2.0 * np.pi / 3.0) * 3.0 / (2.0 * np.pi)
        color[1] = 1.0 - scale
        color[2] = scale

    if angle < -2.0 * np.pi / 3.0:

        real_angle = angle + 2.0 * np.pi
        scale = (real_angle - 2.0 * np.pi / 3.0) * 3.0 / (2.0 * np.pi)
        color[1] = 1.0 - scale
        color[2] = scale

    if angle < 0 and angle >= -2.0 * np.pi / 3.0:

        real_angle = angle + 2.0 * np.pi
        scale = (real_angle - 4.0 * np.pi / 3.0) * 3.0 / (2.0 * np.pi)
        color[2] = 1.0 - scale
        color[0] = scale

    color *= r ** 0.25

    return color    

#transform(TypeSpecialize(checks=False))