diff --git a/docs/releasenotes/2.7.rst b/docs/releasenotes/2.7.rst index 2f4581c25..9e762e1df 100644 --- a/docs/releasenotes/2.7.rst +++ b/docs/releasenotes/2.7.rst @@ -10,6 +10,18 @@ Bicubic and Bilinear downscalling Antialias renamed to Lanczos ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +New :py:attr:`PIL.Image.LANCZOS` constant was added instead of +:py:attr:`PIL.Image.ANTIALIAS`. + +When :py:attr:`~PIL.Image.ANTIALIAS` was initially added, it was the only +high-qality filter based on convolutions. It's name was supposed to reflect +this. Starting from 2.7 all resize method are based on convolutions. All of them +are antialias from now. And the real name of :py:attr:`~PIL.Image.ANTIALIAS` +filter is Lanczos filter. + +:py:attr:`~PIL.Image.ANTIALIAS` constant is leaved for backward compatibility +and is an alias for :py:attr:`~PIL.Image.LANCZOS`. + Lanczos upscaling quality ^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -22,9 +34,28 @@ Resize performance Default filter for thumbnails ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +In Pillow 2.5 default filter for :py:meth:`~PIL.Image.Image.thumbnail` was +changed from :py:attr:`~PIL.Image.NEAREST` to :py:attr:`~PIL.Image.ANTIALIAS`. +Antialias was chosen because all other filters gave poor quality for reduction. +Starting from Pillow 2.7 :py:attr:`~PIL.Image.ANTIALIAS` replaced with +:py:attr:`~PIL.Image.BICUBIC`, because bicubic is faster and +:py:attr:`~PIL.Image.ANTIALIAS` doesn't give any advantages after +downscaling with libJPEG, which uses supersampling internaly, not convolutions. + Image transposing ----------------- +New method :py:attr:`PIL.Image.TRANSPOSE` was added for +:py:meth:`~PIL.Image.Image.transpose` operation in addition to +:py:attr:`~PIL.Image.FLIP_LEFT_RIGHT`, :py:attr:`~PIL.Image.FLIP_TOP_BOTTOM`, +:py:attr:`~PIL.Image.ROTATE_90`, :py:attr:`~PIL.Image.ROTATE_180`, +:py:attr:`~PIL.Image.ROTATE_270`. :py:attr:`~PIL.Image.TRANSPOSE` is algebra +transpose, when image reflected over its main diagonal. + +Speed of :py:attr:`~PIL.Image.ROTATE_90`, :py:attr:`~PIL.Image.ROTATE_270` +and :py:attr:`~PIL.Image.TRANSPOSE` was significantly improved for large images, +which doesn't fit in processor cache. + Gaussian blur and unsharp mask ------------------------------