From f06e4220bcdf774c41fc096c89200a5ca678ea0a Mon Sep 17 00:00:00 2001 From: Jeffrey 'Alex' Clark Date: Thu, 29 Oct 2026 09:08:55 -0400 Subject: [PATCH 1/2] Added release note for resizing vertically first Co-Authored-By: Claude Opus 5.5 --- docs/releasenotes/13.1.0.rst | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/docs/releasenotes/13.1.0.rst b/docs/releasenotes/13.1.0.rst index 7782570bba8..7b1d4f51a19 100644 --- a/docs/releasenotes/13.1.0.rst +++ b/docs/releasenotes/13.1.0.rst @@ -66,6 +66,14 @@ On little-endian systems, :py:meth:`~PIL.Image.Image.resize` read and wrote I;16B and I;16N pixel values in the wrong byte order when using a resampling filter other than ``Resampling.NEAREST``. This has been fixed. +Resizing vertically first +^^^^^^^^^^^^^^^^^^^^^^^^^ + +When the height of an image is being reduced significantly more than the width, +:py:meth:`~PIL.Image.Image.resize` now resamples vertically before horizontally, to +improve performance. Because intermediate values are rounded between the two passes, +pixels may be altered slightly with this change. + Blurring I;16 images ^^^^^^^^^^^^^^^^^^^^ From d8ee63798c08ca6ca48e14f99c453d0e0e4ed7f7 Mon Sep 17 00:00:00 2001 From: Jeffrey 'Alex' Clark Date: Thu, 29 Oct 2026 09:54:28 -0400 Subject: [PATCH 2/2] Moved release note to 13.0.0 Co-Authored-By: Claude Opus 5.5 --- docs/releasenotes/13.0.0.rst | 8 ++++++++ docs/releasenotes/13.1.0.rst | 8 -------- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/docs/releasenotes/13.0.0.rst b/docs/releasenotes/13.0.0.rst index 231689080a4..15ff0ef8c9a 100644 --- a/docs/releasenotes/13.0.0.rst +++ b/docs/releasenotes/13.0.0.rst @@ -300,6 +300,14 @@ applied to RGBA and LA images. Previously, these modes ignored the argument, including when called by :py:meth:`~PIL.Image.Image.thumbnail`, which uses ``reducing_gap=2.0`` by default. +Resizing vertically first +^^^^^^^^^^^^^^^^^^^^^^^^^ + +When the height of an image is being reduced significantly more than the width, +:py:meth:`~PIL.Image.Image.resize` now resamples vertically before horizontally, to +improve performance. Because intermediate values are rounded between the two passes, +pixels may be altered slightly with this change. + Preserved transparency when padding or expanding images in ImageOps ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/docs/releasenotes/13.1.0.rst b/docs/releasenotes/13.1.0.rst index 7b1d4f51a19..7782570bba8 100644 --- a/docs/releasenotes/13.1.0.rst +++ b/docs/releasenotes/13.1.0.rst @@ -66,14 +66,6 @@ On little-endian systems, :py:meth:`~PIL.Image.Image.resize` read and wrote I;16B and I;16N pixel values in the wrong byte order when using a resampling filter other than ``Resampling.NEAREST``. This has been fixed. -Resizing vertically first -^^^^^^^^^^^^^^^^^^^^^^^^^ - -When the height of an image is being reduced significantly more than the width, -:py:meth:`~PIL.Image.Image.resize` now resamples vertically before horizontally, to -improve performance. Because intermediate values are rounded between the two passes, -pixels may be altered slightly with this change. - Blurring I;16 images ^^^^^^^^^^^^^^^^^^^^