[Antartica]

Originally Posted by ericshliao

I think the problem should be caused by the thread for preloading has not completed when shifting to next image.
It has nothing to do with GTK+ or xepdmgr.

I think you can avoid the artifact deactivating the autorefresh while updating the image (that is, using the functions declared in xepdmgrclient.h):

#include "xepdmgrclinet.h"

sEpd *Epd=NULL;

int
main(int argc, char *argv);
{
   if((Epd=EpdInit(NULL))==NULL)
      return(1); /*ERROR */
   /* ... here goes your program ... */
   EpdFini(Epd);
}

int
your_preload_thread()
{
   EpdRefreshAuto(Epd,0);
   /* Do the preload */
   /* ... */
   EpdRefreshAuto(Epd,1);
}

If I have not understood wrongly the problem, that should do it.

But it would be better having the display only updated when the preload has completed, of course .