#undef IMAGE_WALK_UNROLL
#undef IMAGE_WALK_DOUBLE
#undef IMAGE_WALK_EXTRA_ARGS
+#undef IMAGE_WALK_IMAGE
#undef IMAGE_WALK_PIXELS
#undef IMAGE_WALK_COLS
#undef IMAGE_WALK_ROWS
#undef IMAGE_WALK_COL_STEP
#undef IMAGE_WALK_ROW_STEP
+#undef IMAGE_WALK_SEC_IMAGE
#undef IMAGE_WALK_SEC_PIXELS
#undef IMAGE_WALK_SEC_COLS
#undef IMAGE_WALK_SEC_ROWS