[CCV] Created skeleton for exercise 4

Signed-off-by: Jim Martens <github@2martens>

ccv/sheet4/lab_pyramid.cpp

@@ -0,0 +1,29 @@
+#include "lab_pyramid.h"
+
+lab_pyramid::lab_pyramid(cv::String image_filename) {
+  cv::Mat image_rgb = cv::imread(image_filename, cv::IMREAD_COLOR);
+  cv::cvtColor(image_rgb, _inputImage_lab, cv::COLOR_RGB2Lab);
+  cv::split(_inputImage_lab ,_imageChannels);
+};
+
+void lab_pyramid::create_pyramids(int number_of_layers)
+{
+  _pyramids[COLOR_L] = gauss_pyramid(_imageChannels[COLOR_L], number_of_layers);
+  _pyramids[COLOR_A] = gauss_pyramid(_imageChannels[COLOR_A], number_of_layers);
+  _pyramids[COLOR_B] = gauss_pyramid(_imageChannels[COLOR_B], number_of_layers);
+}
+
+gauss_pyramid lab_pyramid::get_pyramid(int channel)
+{
+  switch (channel)
+  {
+    case COLOR_L:
+      return _pyramids[COLOR_L];
+    case COLOR_A:
+      return _pyramids[COLOR_A];
+    case COLOR_B:
+      return _pyramids[COLOR_B];
+    default:
+      throw std::invalid_argument( "received invalid channel value, use COLOR_L, COLOR_A or COLOR_B" );
+  }
+}