Minor.
diff --git a/include/freetype/ftimage.h b/include/freetype/ftimage.h
index 60834b9..6eeefe3 100644
--- a/include/freetype/ftimage.h
+++ b/include/freetype/ftimage.h
@@ -869,7 +869,7 @@ FT_BEGIN_HEADER
*
* @input:
* y ::
- * The scanline's y~coordinate.
+ * The scanline's upward y~coordinate.
*
* count ::
* The number of spans to draw on this scanline.