import io

import picamera

import cv2

import numpy

import math

from UniversalAnalytics import Tracker

size = 1

cv2.namedWindow('Preview')

life=5

face_cascade = cv2.CascadeClassifier('/home/pi/people_counter/lbpcascade_frontalface.xml')

#face_cascade = cv2.CascadeClassifier('/home/pi/people_counter/haarcascade_frontalface_default.xml')

#face_cascade = cv2.CascadeClassifier('hogcascade_pedestrians.xml')

stream = io.BytesIO()

tracker = Tracker.create('UA-123944-30')

def distance(newpoint, oldpoint):

return math.sqrt((newpoint[0] - oldpoint[0]) ** 2 + (newpoint[1] - oldpoint[1]) ** 2)

(oldpoints, opid) = ({}, 0)

with picamera.PiCamera() as camera:

#camera.start_preview()

camera.resolution = (360,240)

camera.rotation = 180

#capture into stream

count = 0

for foo in camera.capture_continuous(stream, format='jpeg', use_video_port=True):

stream.truncate()

stream.seek(0)

#convert image into numpy array

data = numpy.fromstring(stream.getvalue(), dtype=numpy.uint8)

#turn the array into a cv2 image

frame = cv2.imdecode(data, 1)

#convert to grayscale, which is easier

gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)

gray = cv2.equalizeHist(gray)

#look for faces over the given image using the loaded cascade file

faces = face_cascade.detectMultiScale(

gray,

scaleFactor=1.3,

minNeighbors=5,

minSize=(20, 20)

)

todo = [f for f in faces]

sofar = {}

for op in oldpoints:

sofar[op] = ''

extra = []

while todo:

np = todo.pop()

done = False

closest = [(op, distance(np, oldpoints[op][0])) for op in

oldpoints]

closest = [x[0] for x in sorted(closest, key=lambda x: x[1])]

for cop in closest:

if sofar[cop] == '' or distance(np, oldpoints[cop][0]) \

< distance(sofar[cop], oldpoints[cop][0]):

if sofar[cop] != '':

todo.append(sofar[cop])

sofar[cop] = np

done = True

break

if not done:

extra.append(np)

# Update oldpoints

for op in sofar:

if sofar[op] != '':

oldpoints[op] = [sofar[op], life]

else:

oldpoints[op] = [oldpoints[op][0], oldpoints[op][1] - 1]

# Check for any new points

for np in extra:

oldpoints[opid] = [np, life]

opid += 1

#Ping Google Analytics

tracker.send('event', 'Person', 'Detect')

print 'New face detected: {0}'.format(opid);

# Check to kill any

todel = []

for op in oldpoints:

if oldpoints[op][1] == 0:

todel.append(op)

for op in todel:

del oldpoints[op]

for f in oldpoints:

(x, y, w, h) = [v * size for v in oldpoints[f][0]]

dying = 255 // life * (life - oldpoints[f][1])

cv2.rectangle(frame, (x, y), (x + w, y + h), (0 , 255 - dying, dying), 2)

cv2.putText(frame, '%s' % f, (x - 10, y - 10), cv2.FONT_HERSHEY_PLAIN, 1, (255, 255, 255))

cv2.imshow('Preview', frame)

key = cv2.waitKey(10)

if key == 27: # exit on ESC

break

cv2.waitKey(0)

cv2.destroyAllWindows()