title: Python rawpy image saving issues
body: <p>I am experimenting with merging Astrophotography images in python. Currently I have the issue that when exporting an image with different libraries the image has a different color tone than the original. Imported image is in the .nef format.</p>
  
  <p>The code:</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  import cv2
  from scipy import misc
  import rawpy
  from PIL import Image
  import imageio
  
  raw=rawpy.imread("DSC_5817.NEF")
  
  #raw=rawpy.imread("images/1/slika1.cr2")
  rgb=raw.postprocess(no_auto_bright=True)
  
  outfn=".tif"
  
  img=Image.fromarray(rgb)
  
  
  
  img.convert("RGB")
  
  
  img.save("probaPIL"+outfn)
  #
  cv2.imwrite("progaCV2"+outfn, rgb)
  
  misc.imsave("probaSCipi"+outfn, rgb)
  #
  imageio.imsave("probaIMAGEIO"+outfn, rgb)
  
  plt.imsave("probaPLT.tif",rgb )
  
  slika=plt.imread("probaPIL.tif")
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/n6rWP.png" rel="nofollow noreferrer">Screnshot of the output (top middle image is original nef file)</a></p>