generate.py

import sys
from PIL import Image

#将small_img中的像素用近邻法嵌入到big_img中
def my_nearest_resize(big_img, small_img):

    big_w, big_h = big_img.size 
    small_w, small_h = small_img.size 

    dst_im = big_img.copy()

    stepx = big_w/small_w
    stepy = big_h/small_h

    for i in range(0, small_w):
        for j in range(0, small_h):
            map_x = int( i*stepx + stepx*0.5 )
            map_y = int( j*stepy + stepy*0.5 )

            if map_x < big_w and map_y < big_h :
                dst_im.putpixel( (map_x, map_y), small_img.getpixel( (i, j) ) )

    return dst_im



if __name__ == '__main__':
    big_img=Image.open(sys.argv[1])     # 大图
    small_img=Image.open(sys.argv[2])   # 小图

    dst_im = my_nearest_resize(big_img, small_img)
    dst_im.save(sys.argv[3])            # 嵌入小图像素的大图