Full Program

Main

from PIL import Image
import numpy as np
from PIL import ImageChops
import subprocess
import math
import datetime
from PIL import ImageFont
from PIL import ImageDraw
from collections import deque


def image_entropy(prev, curr, smasumm, values):
    im1 = Image.open(prev)
    im2 = Image.open(curr)
    img = ImageChops.difference(im1, im2)

    w, h = img.size
    a = np.array(img.convert('RGB')).reshape((w * h, 3))
    h, e = np.histogramdd(a, bins=(16,) * 3, range=((0, 256),) * 3)
    prob = h / np.sum(h) # normalize
    prob = prob[prob > 0] # remove zeros
    comp = -np.sum(prob * np.log2(prob))
    framsd = SD(values, smasumm)
    information = 'ENT: ' + str('{0:.2f}'.format(comp)) + ' SMA: ' + str('{0:.2f}'.format(smasumm)) + ' LB: ' + str(
        '{0:.2f}'.format(smasumm - framsd)) + ' UB: ' + str('{0:.2f}'.format(smasumm + framsd))
    cimg = Image.open(curr)
    draw = ImageDraw.Draw(cimg)
    font = ImageFont.truetype("arial.ttf", 24)
    draw.text((0, 0), information, (0, 255, 0), font=font)
    cimg.save(curr)
    return comp


def SD(values, mean):
    size = len(values)
    sumsd = 0.0
    for n in range(0, size):
        sumsd += math.sqrt((values[n] - mean) ** 2)
    return math.sqrt((1.0 / (size - 1)) * (sumsd / size))


try:

    print "Initial Image ..."

    time = datetime.datetime.now()
    filename = "image_"
    subprocess.call(
        "raspistill -t 1000 -ex night -awb auto -w 720 -h 480 -o %s" % filename + '1.jpg',
        shell=True)
    prev = filename + '1.jpg'
    i = 1
    summ = smasumm = 0.0
    period = n = 10
    values = deque([0.0] * period)
    while True:
        time = datetime.datetime.now()
        filename = "image_" + str(i) + ".jpg"
        subprocess.call(
            "raspistill -t 1000 -ex night -awb auto -w 720 -h 480 -o %s" % filename,
            shell=True)

        i += 1
        curr = filename
        sma = image_entropy(prev, curr, smasumm, values)
        values.append(sma)
        summ += sma - values.popleft()
        smasumm = summ / n
        prev = curr
        print(datetime.datetime.now() - time)
except KeyboardInterrupt:
    print "  Quit"