python 实现将小图片放到另一个较大的白色或黑色背景图片中

import cv2
import numpy as np

def img_resize_to_target_white(image):
 target = np.ones((224,224),dtype=np.uint8)*255

 ret = cv2.cvtColor(target, cv2.COLOR_GRAY2BGR)

 h = image.shape[0]
 w = image.shape[1]
 for i in range(224):
  for j in range(224):
   if(i < h) and (j < w):

    ret[i, j, 0] = image[i, j, 0]
    ret[i, j, 1] = image[i, j, 1]
    ret[i, j, 2] = image[i, j, 2]
   else:
    ret[i, j, 0] = 255
    ret[i, j, 1] = 255
    ret[i, j, 2] = 255

 return ret
 
if __name__ == '__main__':
 image = cv2.imread('/home/yasin/桌面/test.png')
 img_new_white = img_resize_to_target_white(image)
 cv2.imshow("img_new_white", img_new_white)
 cv2.waitKey() 

import cv2

def img_resize_to_target_black(image):
 target = np.zeros((224,224),dtype=np.uint8)

 bgr_img = cv2.cvtColor(target, cv2.COLOR_GRAY2BGR)

 h = image.shape[0]
 w = image.shape[1]
 for i in range(h):
  for j in range(w):

   bgr_img[i, j, 0] = image[i, j, 0]
   bgr_img[i, j, 1] = image[i, j, 1]
   bgr_img[i, j, 2] = image[i, j, 2]

 return bgr_img

if __name__ == '__main__':
 image = cv2.imread('/home/yasin/桌面/test.png')
 img_new_black = img_resize_to_target_black(image)
 cv2.imshow("img_new_black", img_new_black)
 cv2.waitKey()