1 files changed, 3 insertions, 0 deletions
diff --git a/src/imageutils.cc b/src/imageutils.cc
index 133eaf1..08b0492 100644
--- a/src/imageutils.cc
+++ b/src/imageutils.cc
@@ -1,9 +1,11 @@
 #include "imageutils.h"
 #include <string.h>
 #include <fstream>
+#include <assert>
 
 void flip_image(const unsigned char *src, unsigned char *dst, size_t pixelsize, size_t width, size_t height)
 {
+	assert( src && dst );
 	size_t rowBytes = pixelsize * width;
 	for (size_t i = 0 ; i < height ; i++) {
     memmove(dst + (height - i - 1) * rowBytes, src + i * rowBytes, rowBytes);
@@ -11,6 +13,7 @@ void flip_image(const unsigned char *src, unsigned char *dst, size_t pixelsize,
 }
 
 bool write_png(const char *filename, unsigned char *pixels, int width, int height) {
+	assert( filename && pixels );
   std::ofstream fstream( filename, std::ios::binary );
   if (fstream.is_open()) {
     write_png( fstream, pixels, width, height );