qr.py

import io
import datetime
import time
import picamera
from PIL import Image
import zbar
import cv2
import numpy as np

while True:
# Create the in-memory stream
  stream = io.BytesIO()
  with picamera.PiCamera() as camera:
#    camera.start_preview()
#    time.sleep(1)
    camera.capture(stream, format='jpeg')
# "Rewind" the stream to the beginning so we can read its content
  stream.seek(0)
  pil = Image.open(stream)
  imgGauss = cv2.GaussianBlur(np.asarray(pil), (3,3), 0)
  gray = cv2.cvtColor(imgGauss, cv2.COLOR_RGB2GRAY)
  fm = cv2.Laplacian(gray, cv2.CV_64F).var()
#  print "%d" % fm
  if fm < 100:
    continue

#
#########################################
#
# create a reader
  scanner = zbar.ImageScanner()

# configure the reader
  scanner.parse_config('enable')

  pil = pil.convert('L')
  width, height = pil.size
  raw = pil.tostring()

# wrap image data
  image = zbar.Image(width, height, 'Y800', raw)

# scan the image for barcodes
  scanner.scan(image)

# extract results
  for symbol in image:
    print 'decoded', symbol.type, 'symbol', '"%s"' % symbol.data

# clean up
  del(image)
  pass