title: OpenCV cvtColor CV_BGR2HSV CV_32FC3 Saturation Range
body: <p>I'm trying to build histograms for materials in OpenCV 3.2 but am confused by the HSV ranges--they don't seem to match the documentation, or I am approaching it wrong.</p>
  
  <pre><code>// cv::Mat bgrPhoto contains a test image
  
  cv::Mat3f hsvPhoto;
  bgrPhoto.convertTo(hsvPhoto, CV_32FC3);
  cv::cvtColor(hsvPhoto, hsvPhoto, CV_BGR2HSV, CV_32FC3);
  std::vector&lt;cv::Mat1f&gt; hsvChannels;
  cv::split(hsvPhoto, hsvChannels);
  
  // Documentation [0.0, 1.0]: measured here Hue to 360.0, Sat to 1.0, Val to 255.0
  double minHue, maxHue, minSat, maxSat, minVal, maxVal;
  cv::minMaxIdx(hsvChannels[0], &amp;minHue, &amp;maxHue, 0, 0);
  cv::minMaxIdx(hsvChannels[1], &amp;minSat, &amp;maxSat, 0, 0);
  cv::minMaxIdx(hsvChannels[2], &amp;minVal, &amp;maxVal, 0, 0);
  </code></pre>