Backwards Incompatible Changes¶
Python 3.3 Dropped¶
Python 3.3 is EOL and no longer supported due to moving testing from nose, which is deprecated, to pytest, which doesn’t support Python 3.3. We will not be creating binaries, testing, or retaining compatibility with this version. The final version of Pillow for Python 3.3 is 4.3.0.
Decompression Bombs now raise Exceptions¶
Pillow has previously emitted warnings for images that are
unexpectedly large and may be a denial of service. These warnings are
now upgraded to
DecompressionBombErrors for images that are twice
the size of images that trigger the
default threshold is 128Mpx, or 0.5GB for an
image. This can be disabled or changed by setting
Image.MAX_IMAGE_PIXELS = None.
The olefile module is no longer a required dependency when installing Pillow. Support for plugins requiring olefile will not be loaded if it is not installed. This allows library consumers to avoid installing this dependency if they choose. Some library consumers have little interest in the format support and would like to keep dependencies to a minimum.
Further, the vendored version was removed in Pillow 4.0.0 and replaced with a deprecation warning that PIL.OleFileIO would be removed in a future version. This warning has been upgraded to an import error pending future removal.
Check parameter on _save¶
Several image plugins supported a named
check parameter on their
_save method to preflight if the image could be
saved in that format. That parameter has been removed.
A new named parameter,
fillcolor, has been added to
Image.transform. This color specifies the background color to use in
the area outside the transformed area in the output image. This
parameter takes the same color specifications as used in
Multiframe GIF images now take an optional disposal parameter to specify the disposal option for changed pixels.
Compressed TIFF Images¶
Previously, there were some compression modes (JPEG, Packbits, and
LZW) that were supported with Pillow’s internal TIFF decoder. All
compressed TIFFs are now read using the
libtiff decoder, as it
implements the compression schemes more correctly.
Source Layout Changes¶
The Pillow source is now stored within the
src directory of the
distribution. This prevents accidental imports of the PIL directory
when running Python from the project directory.
Multiarch support on Linux should be more robust, especially on Debian derivatives on ARM platforms. Debian’s multiarch platform configuration is run in preference to the sniffing of machine platform and architecture.