Display a grid of thumbnails.

thumb_grid.py

#!/usr/bin/env python

"""
Display a grid of thumbnails.
"""

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import ImageGrid
import numpy as np
import PIL

def thumb_grid(im_list, grid_shape, scale=0.1, axes_pad=0.07):
    # Grid must be 2D:
    assert len(grid_shape) == 2

    # Make sure all images can fit in grid:
    assert np.prod(grid_shape) >= len(im_list)

    grid = ImageGrid(plt.gcf(), 111, grid_shape, axes_pad=axes_pad)
    for i in range(N):
        data_orig = im_list[i]

        # Scale image:
        im = PIL.Image.fromarray(data_orig)
        thumb_shape = [int(scale*j) for j in im.size]
        im.thumbnail(thumb_shape, PIL.Image.ANTIALIAS)
        data_thumb = np.array(im)
        grid[i].imshow(data_thumb)

        # Turn off axes:
        grid[i].axes.get_xaxis().set_visible(False)
        grid[i].axes.get_yaxis().set_visible(False)
        
if __name__ == '__main__':
    import StringIO
    import requests

    r = requests.get('http://www.storyofmathematics.com/images2/hilbert.jpg')
    im = np.array(PIL.Image.open(StringIO.StringIO(r.content)))

    N = 16
    im_list = [im for i in range(N)]
    thumb_grid(im_list, (4, 4))
    plt.show()