diff --git a/ccv/sheet3/CMakeLists.txt b/ccv/sheet3/CMakeLists.txt
index 9d9ebe8..1f9690b 100644
--- a/ccv/sheet3/CMakeLists.txt
+++ b/ccv/sheet3/CMakeLists.txt
@@ -8,6 +8,8 @@ find_package( OpenCV REQUIRED )
 add_executable(sheet3 main.cpp)
 add_executable(sheet3-exercise1 exercise1.cpp)
 add_executable(sheet3-exercise3 exercise3.cpp)
+add_executable(sheet3-exercise4 gauss_pyramid.cpp lab_pyramid.cpp exercise4.cpp)
 target_link_libraries(sheet3 ${OpenCV_LIBS})
 target_link_libraries(sheet3-exercise1 ${OpenCV_LIBS})
 target_link_libraries(sheet3-exercise3 ${OpenCV_LIBS})
+target_link_libraries(sheet3-exercise4 ${OpenCV_LIBS})
diff --git a/ccv/sheet3/exercise4.cpp b/ccv/sheet3/exercise4.cpp
new file mode 100644
index 0000000..5c3ae9c
--- /dev/null
+++ b/ccv/sheet3/exercise4.cpp
@@ -0,0 +1,35 @@
+#include "lab_pyramid.h"
+
+int main(int argc, char** argv ) {
+  if ( argc != 2 )
+  {
+    printf("usage: <Image_Path>\n");
+    return -1;
+  }
+
+  lab_pyramid pyramid = lab_pyramid(argv[1]);
+  const int number_of_layers = 5;
+  pyramid.create_pyramids(number_of_layers);
+  gauss_pyramid l_pyr = pyramid.get_pyramid(lab_pyramid::COLOR_L);
+  gauss_pyramid a_pyr = pyramid.get_pyramid(lab_pyramid::COLOR_A);
+  gauss_pyramid b_pyr = pyramid.get_pyramid(lab_pyramid::COLOR_B);
+
+  for (int i = 0; i < number_of_layers; i++)
+  {
+    cv::imshow("Channel: L, Layer:" + std::to_string(i), l_pyr.get(i));
+    cv::waitKey(0);
+  }
+
+  for (int i = 0; i < number_of_layers; i++)
+  {
+    cv::imshow("Channel: A, Layer:" + std::to_string(i), a_pyr.get(i));
+    cv::waitKey(0);
+  }
+
+  for (int i = 0; i < number_of_layers; i++)
+  {
+    cv::imshow("Channel: B, Layer:" + std::to_string(i), b_pyr.get(i));
+    cv::waitKey(0);
+  }
+  return 0;
+}
diff --git a/ccv/sheet3/gauss_pyramid.cpp b/ccv/sheet3/gauss_pyramid.cpp
new file mode 100644
index 0000000..b433ef6
--- /dev/null
+++ b/ccv/sheet3/gauss_pyramid.cpp
@@ -0,0 +1,21 @@
+#include "gauss_pyramid.h"
+
+gauss_pyramid::gauss_pyramid() {}
+
+gauss_pyramid::gauss_pyramid(cv::Mat img, int number_of_layers)
+{
+  _layers.push_back(img);
+  cv::Mat blurredImage;
+  cv::Mat resizedImage = img;
+  for (int i = 1; i < number_of_layers; i++)
+  {
+    cv::GaussianBlur(resizedImage, blurredImage, cv::Size(5, 5), 0, 0, cv::BORDER_CONSTANT);
+    cv::resize(blurredImage, resizedImage, cv::Size(), 0.5, 0.5, cv::INTER_NEAREST);
+    _layers.push_back(resizedImage);
+  }
+}
+
+cv::Mat gauss_pyramid::get(int layer)
+{
+  return _layers.at((unsigned long) layer);
+}
diff --git a/ccv/sheet3/gauss_pyramid.h b/ccv/sheet3/gauss_pyramid.h
new file mode 100644
index 0000000..5be6a18
--- /dev/null
+++ b/ccv/sheet3/gauss_pyramid.h
@@ -0,0 +1,17 @@
+#ifndef SHEET3_GAUSS_PYRAMID_H
+#define SHEET3_GAUSS_PYRAMID_H
+
+#include <opencv2/opencv.hpp>
+
+class gauss_pyramid
+{
+private:
+    std::vector<cv::Mat> _layers;
+public:
+    gauss_pyramid();
+    gauss_pyramid(cv::Mat img, int number_of_layers);
+    cv::Mat get(int layer);
+};
+
+
+#endif //SHEET3_GAUSS_PYRAMID_H
diff --git a/ccv/sheet3/lab_pyramid.cpp b/ccv/sheet3/lab_pyramid.cpp
new file mode 100644
index 0000000..19a31b6
--- /dev/null
+++ b/ccv/sheet3/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" );
+  }
+}
diff --git a/ccv/sheet3/lab_pyramid.h b/ccv/sheet3/lab_pyramid.h
new file mode 100644
index 0000000..fe4b74b
--- /dev/null
+++ b/ccv/sheet3/lab_pyramid.h
@@ -0,0 +1,41 @@
+#ifndef SHEET3_LAB_PYRAMID_H
+#define SHEET3_LAB_PYRAMID_H
+
+#include <opencv2/opencv.hpp>
+#include "gauss_pyramid.h"
+
+class lab_pyramid {
+private:
+    cv::Mat _inputImage_lab;
+    cv::Mat _imageChannels[3];
+    gauss_pyramid _pyramids[3];
+public:
+    const static int COLOR_L = 0;
+    const static int COLOR_A = 1;
+    const static int COLOR_B = 2;
+
+    /**
+     * Initializes a LAB pyramid.
+     *
+     * @param image_filename the filename of the image that should be used
+     */
+    lab_pyramid(cv::String image_filename);
+
+    /**
+     * Creates the gaussian pyramids for all channels with the given number of layers each.
+     *
+     * @param number_of_layers number of layers for gaussian pyramid
+     */
+    void create_pyramids(int number_of_layers);
+
+    /**
+     * Before this method can be called, pyramids have to be created via create_pyramids.
+     *
+     * @param channel the channel you want to get (COLOR_L, COLOR_A or COLOR_B)
+     * @return the gaussian_pyramid for the given channel
+     */
+    gauss_pyramid get_pyramid(int channel);
+};
+
+
+#endif //SHEET3_LAB_PYRAMID_H