1 import numpy as np
 2 
 3 def median_filter(input_image, filter_size):
 4     ‘‘‘
 5     中值滤波器
 6     :param input_image: 输入图像
 7     :param filter_size: 滤波器大小
 8     :return: 输出图像
 9 
10     注：此实现滤波器大小必须为奇数且 >= 3
11     ‘‘‘
12     input_image_cp = np.copy(input_image)  # 输入图像的副本
13 
14     pad_num = int((filter_size - 1) / 2)  # 输入图像需要填充的尺寸
15 
16     input_image_cp = np.pad(input_image_cp, (pad_num, pad_num), mode="constant", constant_values=0)  # 填充输入图像
17 
18     m, n = input_image_cp.shape  # 获取填充后的输入图像的大小
19 
20     output_image = np.copy(input_image_cp)  # 输出图像
21 
22     # 空间滤波
23     for i in range(pad_num, m - pad_num):
24         for j in range(pad_num, n - pad_num):
25             output_image[i, j] = np.median(input_image_cp[i - pad_num:i + pad_num + 1, j - pad_num:j + pad_num + 1])
26 
27     output_image = output_image[pad_num:m - pad_num, pad_num:n - pad_num]  # 裁剪
28 
29     return output_image