#%load obr.py 


import pyfits

obr = pyfits.open('barnard_y_0007.fits')
img = obr[0].data
obr.close()

import matplotlib.pyplot as plt

plt.imshow(img)
plt.set_cmap('Greys')

img.mean()
img.std()

# interval 0 .. 1
img1 = (img - 680)/255

# orezani 
img2 = img1
numpy.clip(img1,0.0,1.0,img2)

# sRGB transformace (gamma funkce)
img3 = 1.055*img2**(1/2.4) - 0.055 

#
img4 = img3
numpy.clip(img3,0.0,1.0,img4)

plt.imshow(img4)

# http://matplotlib.org/users/image_tutorial.html