From d68147ce8979b1da05884f98d5ba30d81ae0df2f Mon Sep 17 00:00:00 2001
From: Alexander <homm86@gmail.com>
Date: Tue, 31 Dec 2019 03:35:47 +0300
Subject: [PATCH] Fix rounding error on RGB to L conversion

---
 src/libImaging/Convert.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/libImaging/Convert.c b/src/libImaging/Convert.c
index 60513c66d..9f5722543 100644
--- a/src/libImaging/Convert.c
+++ b/src/libImaging/Convert.c
@@ -44,7 +44,8 @@
 #define L(rgb)\
     ((INT32) (rgb)[0]*299 + (INT32) (rgb)[1]*587 + (INT32) (rgb)[2]*114)
 #define L24(rgb)\
-    ((rgb)[0]*19595 + (rgb)[1]*38470 + (rgb)[2]*7471)
+    ((rgb)[0]*19595 + (rgb)[1]*38470 + (rgb)[2]*7471 + 0x8000)
+
 
 #ifndef round
 double round(double x) {