Presses a key based on activity in UCF Student Union

cam.py

import requests
import binascii
from PIL import Image, ImageFile
import subprocess
r = requests.get("http://webcams.sdes.ucf.edu/webcam/Stream/10", stream=True)

#  Generate Image Object
def gen_image():
	p = ImageFile.Parser()
	start_write = False
	
	for bytes in r.iter_content(2):
		#  Start of file
	    if binascii.hexlify(bytes) == 'ffd8':
	        start_write = True
	    
	    if start_write:
	        p.feed(bytes)
	    
	    #  End of file
	    if binascii.hexlify(bytes) == 'ffd9':
    		return p.close()        	

def difference(im1, im2):
	data1 = im1.getdata()
	data2 = im2.getdata()
	diff = 0
	for i in range(len(data1)):
		diff += abs(data1[i][0] - data2[i][0])
		diff += abs(data1[i][1] - data2[i][1])
		diff += abs(data1[i][2] - data2[i][2])
	return diff 

im = gen_image()
width, height = im.size
#  Setup Crops
top_left = im.crop((0, 0, width/2, height/2))
top_right = im.crop((width/2, 0, width, height/2))
bot_left = im.crop((0, height/2, width/2, height))
bot_right = im.crop((width/2, height/2, width, height))
try:
	#  Baselines
	base_tl = Image.open("top_left.jpg")
	base_tr = Image.open("top_right.jpg")
	base_bl = Image.open("bot_left.jpg")
	base_br = Image.open("bot_right.jpg")

	crop = ""
	diff = 0
	# check differences
	top_left_diff = difference(top_left, base_tl)
	if  top_left_diff > diff:
		diff = top_left_diff
		crop = "top left"

	top_right_diff = difference(top_right, base_tr)
	if  top_right_diff > diff:
		diff = top_right_diff
		crop = "top right"
	bot_left_diff = difference(bot_left, base_bl)
	if  bot_left_diff > diff:
		diff = bot_left_diff
		crop = "bot left"

	bot_right_diff = difference(bot_right, base_br)
	if  bot_right_diff > diff:
		diff = bot_right_diff
		crop = "bot right"
	
	print crop

	if crop == "top left":
		subprocess.call(["xdotool", "key", "a"])
	elif crop == "top right":
		subprocess.call(["xdotool", "key", "b"])
	elif crop == "bot left":
		subprocess.call(["xdotool", "key", "Up"])
	elif crop == "bot right":
		subprocess.call(["xdotool", "key", "Down"])

except:
	print "Run again, baseline images were created."
top_left.save("top_left.jpg")
top_right.save("top_right.jpg")
bot_left.save("bot_left.jpg")
bot_right.save("bot_right.jpg")