title: python tifffile.imsave to save 3 images as 16bit image stack
body: <p>I'm trying to save a numpy array as 16bit image stack using tifffile.imsave. This works perfectly fine for 1,2, or >= 5 images. However, if I try to save 3 or 4 images in one stack, image readers (such as ImageJ) interpret the images as rgb-channels, or as rgb-channels plus one gray value channel, respectively. Is there a way to avoid this e.g. by adding the right flags or tags?</p>
  
  <pre><code>import numpy as np
  from tifffile import imsave
  
  data = np.random.rand(3, 301, 219).astype(np.uint16)
  imsave('myFileName.tif', data)
  </code></pre>