@Test
public void testHistogram() {

  opencv_core.Mat src = LaneManager.readImage(getResourcePath(TEST_IMAGE));
  opencv_core.Mat saturationChannel = LaneManager.getSaturationChannel(src);
  opencv_core.Mat histogram = LaneManager.histogram(saturationChannel);
  assertTrue(LaneManager.writeImage("/tmp/robocar_histogram.jpg", histogram));
  assertEquals(histogram.size().height(), 32);
  assertEquals(histogram.size().width(), 1);
  assertEquals(histogram.rows(), 32);
  assertEquals(histogram.cols(), 1);
}