from VideoCapture import Device
import ImageDraw
import Image
import sys
import pygame
import ImageChops

# init pygame
pygame.init()

# get cam device
cam = Device()

# setup screen size
size = width, height = 320,240


screen = pygame.display.set_mode(size)

while 1:
	for event in pygame.event.get():
		if event.type == pygame.QUIT: sys.exit()
			
	shot = cam.getImage()	
	
	# split the image into individual bands
	source = shot.split()

	R, G, B = 0, 1, 2

	reddata = source[R]
	greendata = source[G]
	bluedata = source[B]

	reddata = reddata.point(lambda i: i > 135 and 200)

	camshot = ImageChops.subtract(reddata, greendata)
	camshot = ImageChops.subtract(camshot, bluedata)

	camshot = camshot.point(lambda i: i > 0 and 255)


	#paste the 3 processed bands back
	source[R].paste(camshot, None)
	source[G].paste(0, None)
	source[B].paste(0, None)

	# build a new multiband image
	camshot = Image.merge(shot.mode, source)			
	
	camshot = pygame.image.fromstring(camshot.tostring(), (320,240), "RGB")
    	screen.blit(camshot, (0,0))
    	pygame.display.flip()