plot several image files in matplotlib subplots

Question

I would like to create a matrix subplot and display each BMP files, from a directory, in a different subplot, but I cannot find the appropriate solution for my problem, could somebody helping me?.

This the code that I have:

import os, sys
from PIL import Image
import matplotlib.pyplot as plt
from glob import glob

bmps = glob('*trace*.bmp')

fig, axes = plt.subplots(3, 3)

for arch in bmps:
    i = Image.open(arch)
    iar = np.array(i)
    for i in range(3):
        for j in range(3):
            axes[i, j].plot(iar)
            plt.subplots_adjust(wspace=0, hspace=0)
plt.show()

I am having the following error after executing:

Answer 1

natively matplotlib only supports PNG images, see http://matplotlib.org/users/image_tutorial.html

then the way is always read the image - plot the image

read image

 img1 = mpimg.imread('stinkbug1.png')
 img2 = mpimg.imread('stinkbug2.png')

plot image (2 subplots)

 plt.figure(1)
 plt.subplot(211)
 plt.imshow(img1)

 plt.subplot(212)
 plt.imshow(img2)
 plt.show()

follow the tutorial on http://matplotlib.org/users/image_tutorial.html (because of the import libraries)

here is a thread on plotting bmps with matplotlib: Why bmp image displayed as wrong color with plt.imshow of matplotlib on IPython-notebook?