python通过pil将图片转换成黑白效果
pil功能强大，convert方法可以轻易的将图片转换，下面的代码可以将图片转换成黑白效果
from PIL import Image
image_file = Image.open("convert_image.png") # open colour image
image_file = image_file.convert('1') # convert image to black and white
image_file.save('result.png')
