Adding borders to an image using python

Question

I have a large number of images of a fixed size (say 500*500). I want to write a python script which will resize them to a fixed size (say 800*800) but will keep the origina

Answer 1

You can load the image with scipy.misc.imread as a numpy array. Then create an array with the desired background with numpy.zeros((height, width, channels)) and paste the image at the desired location:

import numpy as np
import scipy.misc

im = scipy.misc.imread('foo.jpg', mode='RGB')
height, width, channels = im.shape

# make canvas
im_bg = np.zeros((height, width, channels))
im_bg = (im_bg + 1) * 255  # e.g., make it white

# Your work: Compute where it should be
pad_left = ...
pad_top = ...

im_bg[pad_top:pad_top + height,
      pad_left:pad_left + width,
      :] = im
# im_bg is now the image with the background.