From 76b7cddba1d97c22b3a357e2da2f183b3ea1434b Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 20 Mar 2021 12:54:32 +0000
Subject: [PATCH] better rounding in tile calcs

---
 libvips/foreign/jp2kload.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libvips/foreign/jp2kload.c b/libvips/foreign/jp2kload.c
index dbd9d38d..8d22d0fe 100644
--- a/libvips/foreign/jp2kload.c
+++ b/libvips/foreign/jp2kload.c
@@ -592,8 +592,10 @@ vips_foreign_load_jp2k_generate( VipsRegion *out,
 
 	/* jp2k get smaller with the layer size.
 	 */
-	int tile_width = jp2k->info->tdx / jp2k->shrink;
-	int tile_height = jp2k->info->tdy / jp2k->shrink;
+	int tile_width = VIPS_ROUND_UINT( 
+		(double) jp2k->info->tdx / jp2k->shrink );
+	int tile_height = VIPS_ROUND_UINT( 
+		(double) jp2k->info->tdy / jp2k->shrink );
 
 	/* ... so tiles_across is always the same.
 	 */