text: from PIL import Image, ImageDraw, ImageFont
  
  im = Image.open('image.jpg')
  w,h = im.size
  font_size = h/4
  
  draw = ImageDraw.Draw(im)
  fnt = ImageFont.truetype ("Arial.ttf",font_size)
  
  text_w,text_h = draw.textsize("8",font=fnt) # 给定文字message，返回所占像素(width,height)
  
  draw.text((w-text_w,0), "8", fill=(255,0,0), font=fnt)#图片宽度减去字体宽度、要写的字符、颜色、字体
  
  
  im.save('image_1.jpg')
  
  #reference http://www.cnblogs.com/wei-li/archive/2012/04/19/2456725.html