Python PIL cut off my 16-bit grayscale image at 8-bit

Question

I'm working on an python program to display images of stars. The images are 16-bit grayscale tiffs. If I try to display them in an extern program, eg ImageMagick they are correct but if I load them in python and then use 'show()' or implement them in a canvas in Tkinter they are, unless a few pixel, totally white. So I estimate python sets every pixel above 255 to white but I don't know why. If I load the image and then save it as tiff again, ImageMagick can show it correct. Thanks for help.

Answer 1

Try to convert the image to a numpy array and display that:

import Image
import matplotlib.pyplot as plt
import numpy as np

img = Image.open('image.tiff')
arr = np.asarray(img.getdata()).reshape(img.size[1], img.size[0])
plt.imshow(arr)
plt.show()

You can change the color mapping too:

from matplotlib import cm
plt.imshow(arr, cmap=cm.gray)