Processing RGB Image in Python

import Image

im=Image.open('c:/House24.png')

source=im.split()

R, G, B = 0, 1, 2

# Select regions where red is less than 100

mask = source[R].point(lambda i: i < 100 and 255)

# process the green band

out=source[G].point(lambda i: i * 0.7)

# paste the processed band back, but only where red was < 100

source[G].paste(out,None,mask)

# build a new multiband image

im = Image.merge(im.mode,source)

im.show(im)

import Image

im=Image.open('c:/House24.png')

source=im.split()

R, G, B = 0, 1, 2

# Select regions where red is less than 100

mask = source[R].point(lambda i: i < 100 and 255)

# process the green band

out=source[G].point(lambda i: i * 0.7)

# paste the processed band back, but only where red was < 100

source[G].paste(out,None,mask)

# build a new multiband image

im = Image.merge(im.mode,source)

im.show(im)