如何消除图像拼接融合时产生的黑色线条伪影？

我近期开展了一个需拼接融合多张图像的项目，已完成所有必要步骤并成功拼接图像，但发现最终图像的各拼接块边缘出现黑色线条伪影，清晰显示出各图像的拼接位置，这些伪影一眼就能察觉。

我的图像拼接融合代码如下：

def normalize_piece(img):
    return cv2.normalize(img.astype('float'), None, 0.0, 1.0, cv2.NORM_MINMAX)


def blend_pieces(piece1, piece2, transformation_matrix, width, height):
    piece1_norm = normalize_piece(piece1)
    piece2_norm = normalize_piece(piece2)

    piece1_warped = cv2.warpPerspective(src=piece1_norm, M=transformation_matrix, dsize=(width, height))

    black_rgb_pixel = np.zeros(3)
    mask_left = np.all(piece1_warped != black_rgb_pixel, axis=-1)
    mask_right = np.all(piece2_norm != black_rgb_pixel, axis=-1)

    mask_overlap = mask_left & mask_right
    mask_left_only = mask_left & ~mask_right
    mask_right_only = mask_right & ~mask_left

    piece1_warped[mask_left_only] = piece1_warped[mask_left_only]
    piece1_warped[mask_right_only] = piece2_norm[mask_right_only]
    piece1_warped[mask_overlap] = (piece1_warped[mask_overlap] + piece2_norm[mask_overlap]) / 2

    return piece1_warped

补充说明：我有3张待拼接的图像块，需要先拼接part1与part2，再将拼接结果与part3融合。

内容的提问来源于stack exchange，提问作者Straw User