from PIL import Image
import sys
#先將 input image 填充為正方形
def fill_image(image):
  width, height = image.size
  #選取長和寬中較大值作為新圖片的
  new_image_length = width if width > height else height
  #生成新圖片[白底]
  new_image = Image.new(image.mode, (new_image_length, new_image_length), color='white')  #注意這個函數！
  #將之前的圖粘貼在新圖上，居中
  if width > height:#原圖寬大于高，則填充圖片的豎直維度 #(x,y)二元組表示粘貼上圖相對下圖的起始位置,是個坐標點。
    new_image.paste(image, (0, int((new_image_length - height) / 2)))
  else:
    new_image.paste(image, (int((new_image_length - width) / 2),0))
  return new_image
def cut_image(image):
  width, height = image.size
  item_width = int(width / 3) #因為朋友圈一行放3張圖。
  box_list = []
  # (left, upper, right, lower)
  for i in range(0,3):
    for j in range(0,3):
      #print((i*item_width,j*item_width,(i+1)*item_width,(j+1)*item_width))
      box = (j*item_width,i*item_width,(j+1)*item_width,(i+1)*item_width)
      box_list.append(box)
  image_list = [image.crop(box) for box in box_list]
  return image_list
#保存
def save_images(image_list):
  index = 1
  for image in image_list:
    image.save(str(index) + '.png', 'PNG')
    index += 1
if __name__ == '__main__':
  file_path = "2.jpg" #圖片保存的地址
  image = Image.open(file_path)
  #image.show()
  image_new = fill_image(image)
  image_list = cut_image(image_new)
  save_images(image_list)