Index: Source/System/Image/WS/OSGImage.cpp
===================================================================
--- Source/System/Image/WS/OSGImage.cpp	(revision 2742)
+++ Source/System/Image/WS/OSGImage.cpp	(revision 2743)
@@ -407,6 +407,9 @@
 void Image::clearData(void)
 {
     editMFPixel()->clear();
+    // free unused memory.
+    MFUInt8 tmp;
+    tmp.swap(*editMFPixel());
 }
 
 /*! method to update just a subregion of the image data