diff -urp yagf-0.9.5/src/core/qipgrayscaleimage.cpp yagf-0.9.5-nothreads/src/core/qipgrayscaleimage.cpp
--- yagf-0.9.5/src/core/qipgrayscaleimage.cpp	2015-02-17 07:50:24.000000000 +0600
+++ yagf-0.9.5-nothreads/src/core/qipgrayscaleimage.cpp	2017-03-22 10:06:34.427939051 +0700
@@ -27,7 +27,7 @@
 #include <QtConcurrentRun>
 
 
-#define IPRIT_MULTITHREADING
+//#define IPRIT_MULTITHREADING
 
 const QString fheader = QString::fromUtf8("YGF1");