title: How to remove normalization from scipy imsave function
body: <p>I have a simple task to accomplish, but the current save functions I am finding are not helping me at all. What I have to do is simply convert a gray-scale image to another one which has intensities belonging to a smaller interval (specifically between 120 and 180). </p>
  
  <p>I implemented the conversion (like a changing different temperature scales), but when I save the image, scipy.misc.imsave normalizes it. The conversion is correct because I created histograms to display the intensities before the saving, and they are all lying between the specified range. </p>
  
  <p>I've tried other tools like: </p>
  
  <pre><code>imageio.imwrite(path, img)
  numpy.save(path, img)
  scipy.misc.toimage(img, cmin=120, cmax=180, mode='L').save(path)
  </code></pre>
  
  <p>I confess this last one I don't understand the parameters quite well (I have a guess), and the <a href="https://docs.scipy.org/doc/scipy-0.18.1/reference/generated/scipy.misc.toimage.html" rel="nofollow noreferrer">documentation</a> didn't help. Could anybody help me with this issue? </p>
  
  <p>EDIT: I am posting the code</p>
  
  <pre><code>def ex3():
      I = misc.imread(imgname)
      N =  numpy.multiply(I , float(12.0/51.0))
      N = numpy.add(N, 120)
      NEG = I
      NEG = numpy.add(NEG, -255)
      NEG = numpy.absolute(NEG)
      misc.imsave(path, N)
      misc.imsave(os.getcwd()+"/a0/results/"+file.replace(path, NEG)
  </code></pre>
  
  <p>The image was perfectly rendered when I switched to OpenCV. But I would like to stick with Scipy if possible.</p>