python - 有没有一种好的方法可以在不检查边界符号的情况下对 Python numpy ndarrays 进行切片？

Question

这是我一直致力于快速对齐图像的一些代码的一部分。它运行良好，但语法很丑陋。有更好的写法吗？

def shift_int(image, base, y, x):
    """
    Quickly shift an image with respect to a base and return a parameter that
    is minimized when the images are well aligned, and not biased towards
    large shifts

    image -- The input image that is shifted
    base -- The second image to match
    y -- An offset along axis 0
    x -- An offset along axis 1
    """
    new_image = image.copy()
    new_base = base.copy()

    if y > 0:
        new_image = new_image[:-y]
        new_base = new_base[y:]

    if y < 0:
        new_image = new_image[-y:]
        new_base = new_base[:y]

    if x > 0:
        new_image = new_image[:,:-x]
        new_base = new_base[:,x:]

    if x < 0:
        new_image = new_image[:,-x:]
        new_base = new_base[:,:x]

    return np.mean((new_im-new_base)**2)

Answer 1

h, w = np.shape(new_image)
new_image = new_image[max(0, -y):min(h, h-y),max(0, -x):min(w, w-x)]

h, w = np.shape(new_base)
new_base = new_base[max(0, y):min(h, h+y),max(0, x):min(w, w+x)]