#!/usr/bin/env python

import Image, ImageMath

import im_debug

im = Image.open('./image.jpg')
im_debug.show(im, 'Original image')

im_l = im.convert('L')
im_debug.show(im_l, 'ITU-R 601-2 luma transform')

im_rgb = im.convert('L', (float(1)/3, float(1)/3, float(1)/3, 0))
im_debug.show(im_rgb, '(R+G+B)/3 transform')

s1, s2 = im.size
im2 = Image.new('L', (s1 * 2, s2))
im2.paste(im_l, (0, 0, s1, s2))
im2.paste(im_rgb, (s1, 0, 2*s1, s2))
im_debug.show(im2, 'Both transforms side by side')

im_debug.show(ImageMath.eval("convert(abs(a - b)*5, 'L')", a=im_l, b=im_rgb), 'Difference')