title: Create RGB image with three grayscale png files - pypng
body: <p>I'm trying to create an RGB png image by merging three grayscale png images using <code>pypng</code>. I've read the png files into numpy arrays as below</p>
  
  <pre><code>pngFile1 = png.Reader("file1.png").read()
  pngFile2 = png.Reader("file2.png").read()
  pngFile3 = png.Reader("file3.png").read()
  
  pngArray1 = np.array(list(pngFile1[2]))
  pngArray2 = np.array(list(pngFile2[2]))
  pngArray3 = np.array(list(pngFile3[2]))
  </code></pre>
  
  <p>How do I combine these three arrays/images to recreate an RGB png image?</p>