import Image
import tkFileDialog

# Input and output file setup
files = tkFileDialog.askopenfilenames()
outfile = 'ask'

# Read images
images = []
w = 0
h = 0
for file in files:
    image = Image.open(file)
    w += image.size[0]
    height = image.size[1]
    if height > h:
        h = height
    images.append(image)

# Write composed image
if w > 0 and h > 0:
    composition = Image.new('RGBA',(w,h))
    x = 0
    for image in images:
        composition.paste(image,(x,0,x+image.size[0],image.size[1]))
        x += image.size[0]
    if outfile == 'ask':
        outfile = tkFileDialog.asksaveasfilename()    
    composition.save(outfile)
    
print "Done!"