Index: trunk/stac/src/stacRejection.c
===================================================================
--- trunk/stac/src/stacRejection.c	(revision 3375)
+++ trunk/stac/src/stacRejection.c	(revision 3387)
@@ -110,6 +110,6 @@
 		if (region->data.U8[y][x]) {
 
-		    inCoords->x = (double)x;
-		    inCoords->y = (double)y;
+		    inCoords->x = (double)x + 0.5;
+		    inCoords->y = (double)y + 0.5;
 		    (void)psPlaneTransformApply(outCoords, map, inCoords);
 		    float maskVal = (float)psImagePixelInterpolate(reject, outCoords->x, outCoords->y,