[CVV] Added ability to get layers of laplacian pyramid

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

ccv/sheet5/laplacian_pyramid.cpp

@@ -9,3 +9,11 @@ laplacian_pyramid::laplacian_pyramid(const gauss_pyramid &pyramid, float sigma)
     _layers.push_back(pyramid.get(i) - blurred);
   }
 }
+
+cv::Mat laplacian_pyramid::get(int layer) const {
+  return _layers.at((unsigned long) layer);
+}
+
+unsigned long laplacian_pyramid::get_number_of_layers() const {
+  return _layers.size();
+}