title: HSV2BGR conversion fails in Python OpenCV script
body: <p>My script is supposed to take a greyscale image and map the values to hues.</p>
  
  <pre><code>#!/usr/bin/env python
  
  import cv2
  import numpy
  
  infile = cv2.imread('Lenna.png')
  
  infile = infile[:,:,0]
  
  hues = (numpy.array(infile)/255.)*179
  
  outimageHSV = numpy.array([[[b,255,255] for b in a] for a in hues]).astype(int)
  
  outimageBGR = cv2.cvtColor(outimageHSV, cv2.COLOR_HSV2BGR)
  
  cv2.imshow('dst_rt', outimageBGR)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  </code></pre>
  
  <p>It fails on the line with cvtColor and I get this error: </p>
  
  <pre><code>OpenCV Error: Assertion failed (depth == CV_8U || depth == CV_16U || depth == CV_32F) in cvtColor, file /tmp/opencv20150506-38415-u2kidu/opencv-2.4.11/modules/imgproc/src/color.cpp, line 3644
  Traceback (most recent call last):
    File "luma2hue.py", line 16, in &lt;module&gt;
      outimageBGR = cv2.cvtColor(outimageHSV, cv2.COLOR_HSV2BGR)
  cv2.error: /tmp/opencv20150506-38415-u2kidu/opencv-2.4.11/modules/imgproc/src/color.cpp:3644: error: (-215) depth == CV_8U || depth == CV_16U || depth == CV_32F in function cvtColor
  </code></pre>
  
  <p>Do I need to do something else to my outimageHSV array to make it ready for cvtColor?</p>