star_checker.py 文件源码

def renderStarGauss(image, cov, mu, first, scale = 5):
    num_circles = 3
    num_points = 64

    cov = sqrtm(cov)

    num = num_circles * num_points
    pos = np.ones((num, 2))

    for c in range(num_circles):
        r = c + 1
        for p in range(num_points):
            angle = p / num_points * 2 * np.pi
            index = c * num_points + p

            x = r * np.cos(angle)
            y = r * np.sin(angle)

            pos[index, 0] = x * cov[0, 0] + y * cov[0, 1] + mu[0]
            pos[index, 1] = x * cov[1, 0] + y * cov[1, 1] + mu[1]

    #image = image.copy()
    #image = cv2.cvtColor(image, cv2.COLOR_GRAY2BGR)

    if first:
        image = cv2.resize(image, (0, 0), None, scale, scale, cv2.INTER_NEAREST)

    for c in range(num_circles):
        pts = np.array(pos[c * num_points:(c + 1) * num_points, :] * scale + scale / 2, np.int32)
        pts = pts.reshape((-1,1,2))
        cv2.polylines(image, [pts], True, (255, 0, 0))

    return image