[Python] NumPy, PIL adding an image

I'm trying to add two images together using NumPy and PIL. The way I would do this in MATLAB would be something like:

>> M1 = imread('_1.jpg');
>> M2 = imread('_2.jpg');
>> resM = M1 + M2;
>> imwrite(resM, 'res.jpg');


I get something like this:

alt text http://www.deadlink.cc/matlab.jpg

Using a compositing program and adding the images the MATLAB result seems to be right.

In Python I'm trying to do the same thing like this:

from PIL import Image
from numpy import *

im1 = Image.open('/Users/rem7/Desktop/_1.jpg')
im2 = Image.open('/Users/rem7/Desktop/_2.jpg')

im1arr = asarray(im1)
im2arr = asarray(im2)

addition = im1arr + im2arr

resultImage = Image.fromarray(addition)
resultImage.save('/Users/rem7/Desktop/a.jpg')


and I get something like this:

alt text http://www.deadlink.cc/python.jpg

Why am I getting all those funky colors? I also tried using ImageMath.eval("a+b", a=im1, b=im2), but I get an error about RGB unsupported.

I also saw that there is an Image.blend() but that requires an alpha.

What's the best way to achieve what I'm looking for?

Source Images (images have been removed):

alt text http://www.deadlink.cc/_1.jpg alt text http://www.deadlink.cc/_2.jpg

Humm, OK, well I added the source images using the add image icon and they show up when I'm editing the post, but for some reason the images don't show up in the post.

(images have been removed) 2013 05 09

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