--- a/filter/raster.c
+++ b/filter/raster.c
@@ -460,9 +460,9 @@
 
 	  while (count > 0)
 	  {
-	    memcpy(temp, temp - r->bpp, r->bpp);
-	    temp  += r->bpp;
-	    count -= r->bpp;
+	    *temp = *(temp - r->bpp);
+	    temp  += 1;
+	    count -= 1;
           }
 	}
       }