edgetaper implementation in numpy/opencv

edgetaper.py

# this is a python reimplementation of edgetaper introduced here: https://docs.opencv.org/4.x/d1/dfd/tutorial_motion_deblur_filter.html
def edgetaper(img, gamma=5, beta=0.2):
    width,height = img.shape[:2]
    dx = 2 * np.pi / width
    dy = 2 * np.pi / height
    # subtract dx and dy to match original function's range
    x = np.linspace(-np.pi, np.pi-dx, width)
    y = np.linspace(-np.pi, np.pi-dy, height)
    w1 = 0.5 * (np.tanh((x + gamma / 2) / beta) - np.tanh((x - gamma / 2) / beta))
    w2 = 0.5 * (np.tanh((y + gamma / 2) / beta) - np.tanh((y - gamma / 2) / beta))
    w = np.dot(w2.reshape(-1, 1), w1.reshape(1, -1))    
    if img.ndim>2:
        w = w[:, :, np.newaxis].repeat(img.shape[2], axis=2)
    return cv2.multiply(img.astype(np.float32), w.astype(np.float32)).clip(0,255).astype(np.uint8)