diff --git a/CMakeLists.txt b/CMakeLists.txt
index 03bf32a..00c5a7c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,6 +5,8 @@ project(libravatarserv
 )
 
 include(GNUInstallDirs)
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(LIBPNG REQUIRED libpng)
 
 set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
@@ -13,6 +15,9 @@ set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wall -g -Og")
 
 include_directories(${PROJECT_BINARY_DIR})
+include_directories(${LIBPNG_INCLUDE_DIRS})
+
+link_directories(${LIBPNG_LIBRARY_DIRS})
 
 # Write version in header
 configure_file(
@@ -22,5 +27,5 @@ configure_file(
 
 file(GLOB sources src/*.cpp)
 add_executable(${CMAKE_PROJECT_NAME} ${sources})
-#target_link_libraries(${CMAKE_PROJECT_NAME})
+target_link_libraries(${CMAKE_PROJECT_NAME} ${LIBPNG_LIBRARIES})
 install(TARGETS ${CMAKE_PROJECT_NAME} DESTINATION ${CMAKE_INSTALL_BINDIR})
diff --git a/src/libravatarserv.cpp b/src/libravatarserv.cpp
index d901d4e..a515ae6 100644
--- a/src/libravatarserv.cpp
+++ b/src/libravatarserv.cpp
@@ -14,14 +14,20 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <cstdlib>  // getenv()
 #include <iostream>
+#include <cstdlib>  // getenv()
+#include <png++/png.hpp>
 
 using std::cout;
 
 int main(int argc, char *argv[])
 {
-    cout << "Content-type: text/plain\r\n\r\n";
+    cout << "Content-type: image/png\r\n\r\n";
     cout << std::getenv("REQUEST_URI") << "\r\n";
+
+    png::image<png::rgba_pixel> image(argv[1]);
+
+    image.write("/dev/stdout");
+
     return 0;
 }