how to read in png into n x n-array with predefined value of "n" in matplotlib using imread

The following reads in a png into an array:

import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import numpy as np

img=mpimg.imread('example.png')

the result is the array img, which is e.g. a 1024 x 1024-array of tuples (see http://matplotlib.org/1.3.1/users/image_tutorial.html):

How I can enforce, that my result is an n x n-array (of tuples) instead of the 1024 x 1024-array (n<1024)? I need to explicitly define the dimension of that array (e.g. set 400x400).

Thanks in advance

Solution

I recommend installing pillow (preferably using Anaconda). It makes image manipulation easy — mostly easier than treating the image as a raw ndarray.

Once you have pillow installed, this answer should help: How do I resize an image using PIL and maintain its aspect ratio?

If you really want to keep it as an array, then you could use scipy.misc.imresize.

Edit to add the thing that actually worked, in case others miss it:

import scipy.misc
img_rescaled = scipy.misc.imresize(img, size=[400,400], interp='bilinear')