sudo apt-get install libopencv-*
sudo apt-get install python-opencv
sudo apt-get install python-numpy

import os
import os
from PIL import Image,ImageDraw
import cv

def detect_object(image):
  grayscale = cv.CreateImage((image.width,image.height),8,1)#创建空的灰度值图片
  cv.CvtColor(image,grayscale,cv.CV_BGR2GRAY)
  cascade=cv.Load("/usr/share/opencv/haarcascades/haarcascade_frontalface_alt_tree.xml")#记载特征值库，此目录下还有好多库可以选用
  rect=cv.HaarDetectObjects(grayscale,cascade,cv.CreateMemStorage(),1.1,2,cv.CV_HAAR_DO_CANNY_PRUNING,(20,20))
  result=[]#标记位置
  for r in rect:
    result.append((r[0][0],r[0][1],r[0][0]+r[0][2],r[0][1]+r[0][3]))
  return result

def process(infile):
  image = cv.LoadImage(infile)
  if image:
    faces = detect_object(image)
  im = Image.open(infile)
  path = os.path.abspath(infile)
  save_path = os.path.splitext(path)[0]+"_face"
  try:
    os.mkdir(save_path)
  except:
    pass
  if faces:
    draw = ImageDraw.Draw(im)
    count=0
    for f in faces:
       count+=1
       draw.rectangle(f,outline=(255,0,0))
       a=im.crop(f)
       file_name=os.path.join(save_path,str(count)+".jpg")
       a.save(file_name)
    drow_save_path = os.path.join(save_path,"out.jpg")
    im.save(drow_save_path,"JPEG",quality=80)
  else:
    print "Error: cannot detect faces on %s" % infile
if __name__ == "__main__":
   process("test3.jpg")