--- Source/mainPng.cpp.orig	2010-04-08 01:45:30.000000000 +0900
+++ Source/mainPng.cpp	2013-10-28 05:55:25.000000000 +0900
@@ -27,6 +27,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sstream>
+#include <unistd.h>
 
 
 using namespace std;