python-pillow/Pillow
1
1
Fork 0
mirror of https://github.com/python-pillow/Pillow.git synced 2024-12-27 02:16:19 +03:00
Code Issues Packages Projects Releases Wiki Activity
d55563ca25
Pillow/docs/reference/Image.rst
Andrew Murray d3d7566d9a Refer to Resampling enum
2023-01-07 11:27:43 +11:00

506 lines
14 KiB
ReStructuredText
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

.. py:module:: PIL.Image
.. py:currentmodule:: PIL.Image
:py:mod:`~PIL.Image` Module
===========================
The :py:mod:`~PIL.Image` module provides a class with the same name which is
used to represent a PIL image. The module also provides a number of factory
functions, including functions to load images from files, and to create new
images.
Examples
--------
Open, rotate, and display an image (using the default viewer)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The following script loads an image, rotates it 45 degrees, and displays it
using an external viewer (usually xv on Unix, and the Paint program on
Windows).
.. code-block:: python
from PIL import Image
with Image.open("hopper.jpg") as im:
im.rotate(45).show()
Create thumbnails
^^^^^^^^^^^^^^^^^
The following script creates nice thumbnails of all JPEG images in the
current directory preserving aspect ratios with 128x128 max resolution.
.. code-block:: python
from PIL import Image
import glob, os
size = 128, 128
for infile in glob.glob("*.jpg"):
file, ext = os.path.splitext(infile)
with Image.open(infile) as im:
im.thumbnail(size)
im.save(file + ".thumbnail", "JPEG")
Functions
---------
.. autofunction:: open
.. warning::
To protect against potential DOS attacks caused by "`decompression bombs`_" (i.e. malicious files
which decompress into a huge amount of data and are designed to crash or cause disruption by using up
a lot of memory), Pillow will issue a ``DecompressionBombWarning`` if the number of pixels in an
image is over a certain limit, :py:data:`MAX_IMAGE_PIXELS`.
This threshold can be changed by setting :py:data:`MAX_IMAGE_PIXELS`. It can be disabled
by setting ``Image.MAX_IMAGE_PIXELS = None``.
If desired, the warning can be turned into an error with
``warnings.simplefilter('error', Image.DecompressionBombWarning)`` or suppressed entirely with
``warnings.simplefilter('ignore', Image.DecompressionBombWarning)``. See also
`the logging documentation`_ to have warnings output to the logging facility instead of stderr.
If the number of pixels is greater than twice :py:data:`MAX_IMAGE_PIXELS`, then a
``DecompressionBombError`` will be raised instead.
.. _decompression bombs: https://en.wikipedia.org/wiki/Zip_bomb
.. _the logging documentation: https://docs.python.org/3/library/logging.html#integration-with-the-warnings-module
Image processing
^^^^^^^^^^^^^^^^
.. autofunction:: alpha_composite
.. autofunction:: blend
.. autofunction:: composite
.. autofunction:: eval
.. autofunction:: merge
Constructing images
^^^^^^^^^^^^^^^^^^^
.. autofunction:: new
.. autofunction:: fromarray
.. autofunction:: frombytes
.. autofunction:: frombuffer
Generating images
^^^^^^^^^^^^^^^^^
.. autofunction:: effect_mandelbrot
.. autofunction:: effect_noise
.. autofunction:: linear_gradient
.. autofunction:: radial_gradient
Registering plugins
^^^^^^^^^^^^^^^^^^^
.. note::
These functions are for use by plugin authors. Application authors can
ignore them.
.. autofunction:: register_open
.. autofunction:: register_mime
.. autofunction:: register_save
.. autofunction:: register_save_all
.. autofunction:: register_extension
.. autofunction:: register_extensions
.. autofunction:: registered_extensions
.. autofunction:: register_decoder
.. autofunction:: register_encoder
The Image Class
---------------
.. autoclass:: PIL.Image.Image
An instance of the :py:class:`~PIL.Image.Image` class has the following
methods. Unless otherwise stated, all methods return a new instance of the
:py:class:`~PIL.Image.Image` class, holding the resulting image.
.. automethod:: PIL.Image.Image.alpha_composite
.. automethod:: PIL.Image.Image.apply_transparency
.. automethod:: PIL.Image.Image.convert
The following example converts an RGB image (linearly calibrated according to
ITU-R 709, using the D65 luminant) to the CIE XYZ color space:
.. code-block:: python
rgb2xyz = (
0.412453, 0.357580, 0.180423, 0,
0.212671, 0.715160, 0.072169, 0,
0.019334, 0.119193, 0.950227, 0)
out = im.convert("RGB", rgb2xyz)
.. automethod:: PIL.Image.Image.copy
.. automethod:: PIL.Image.Image.crop
This crops the input image with the provided coordinates:
.. code-block:: python
from PIL import Image
with Image.open("hopper.jpg") as im:
# The crop method from the Image module takes four coordinates as input.
# The right can also be represented as (left+width)
# and lower can be represented as (upper+height).
(left, upper, right, lower) = (20, 20, 100, 100)
# Here the image "im" is cropped and assigned to new variable im_crop
im_crop = im.crop((left, upper, right, lower))
.. automethod:: PIL.Image.Image.draft
.. automethod:: PIL.Image.Image.effect_spread
.. automethod:: PIL.Image.Image.entropy
.. automethod:: PIL.Image.Image.filter
This blurs the input image using a filter from the ``ImageFilter`` module:
.. code-block:: python
from PIL import Image, ImageFilter
with Image.open("hopper.jpg") as im:
# Blur the input image using the filter ImageFilter.BLUR
im_blurred = im.filter(filter=ImageFilter.BLUR)
.. automethod:: PIL.Image.Image.frombytes
.. automethod:: PIL.Image.Image.getbands
This helps to get the bands of the input image:
.. code-block:: python
from PIL import Image
with Image.open("hopper.jpg") as im:
print(im.getbands()) # Returns ('R', 'G', 'B')
.. automethod:: PIL.Image.Image.getbbox
This helps to get the bounding box coordinates of the input image:
.. code-block:: python
from PIL import Image
with Image.open("hopper.jpg") as im:
print(im.getbbox())
# Returns four coordinates in the format (left, upper, right, lower)
.. automethod:: PIL.Image.Image.getchannel
.. automethod:: PIL.Image.Image.getcolors
.. automethod:: PIL.Image.Image.getdata
.. automethod:: PIL.Image.Image.getexif
.. automethod:: PIL.Image.Image.getextrema
.. automethod:: PIL.Image.Image.getpalette
.. automethod:: PIL.Image.Image.getpixel
.. automethod:: PIL.Image.Image.getprojection
.. automethod:: PIL.Image.Image.histogram
.. automethod:: PIL.Image.Image.paste
.. automethod:: PIL.Image.Image.point
.. automethod:: PIL.Image.Image.putalpha
.. automethod:: PIL.Image.Image.putdata
.. automethod:: PIL.Image.Image.putpalette
.. automethod:: PIL.Image.Image.putpixel
.. automethod:: PIL.Image.Image.quantize
.. automethod:: PIL.Image.Image.reduce
.. automethod:: PIL.Image.Image.remap_palette
.. automethod:: PIL.Image.Image.resize
This resizes the given image from ``(width, height)`` to ``(width/2, height/2)``:
.. code-block:: python
from PIL import Image
with Image.open("hopper.jpg") as im:
# Provide the target width and height of the image
(width, height) = (im.width // 2, im.height // 2)
im_resized = im.resize((width, height))
.. automethod:: PIL.Image.Image.rotate
This rotates the input image by ``theta`` degrees counter clockwise:
.. code-block:: python
from PIL import Image
with Image.open("hopper.jpg") as im:
# Rotate the image by 60 degrees counter clockwise
theta = 60
# Angle is in degrees counter clockwise
im_rotated = im.rotate(angle=theta)
.. automethod:: PIL.Image.Image.save
.. automethod:: PIL.Image.Image.seek
.. automethod:: PIL.Image.Image.show
.. automethod:: PIL.Image.Image.split
.. automethod:: PIL.Image.Image.tell
.. automethod:: PIL.Image.Image.thumbnail
.. automethod:: PIL.Image.Image.tobitmap
.. automethod:: PIL.Image.Image.tobytes
.. automethod:: PIL.Image.Image.transform
.. automethod:: PIL.Image.Image.transpose
This flips the input image by using the :data:`Transpose.FLIP_LEFT_RIGHT`
method.
.. code-block:: python
from PIL import Image
with Image.open("hopper.jpg") as im:
# Flip the image from left to right
im_flipped = im.transpose(method=Image.Transpose.FLIP_LEFT_RIGHT)
# To flip the image from top to bottom,
# use the method "Image.Transpose.FLIP_TOP_BOTTOM"
.. automethod:: PIL.Image.Image.verify
.. automethod:: PIL.Image.Image.load
.. automethod:: PIL.Image.Image.close
Image Attributes
----------------
Instances of the :py:class:`Image` class have the following attributes:
.. py:attribute:: Image.filename
:type: str
The filename or path of the source file. Only images created with the
factory function ``open`` have a filename attribute. If the input is a
file like object, the filename attribute is set to an empty string.
.. py:attribute:: Image.format
:type: Optional[str]
The file format of the source file. For images created by the library
itself (via a factory function, or by running a method on an existing
image), this attribute is set to :data:`None`.
.. py:attribute:: Image.mode
:type: str
Image mode. This is a string specifying the pixel format used by the image.
Typical values are “1”, “L”, “RGB”, or “CMYK.” See
:ref:`concept-modes` for a full list.
.. py:attribute:: Image.size
:type: tuple[int]
Image size, in pixels. The size is given as a 2-tuple (width, height).
.. py:attribute:: Image.width
:type: int
Image width, in pixels.
.. py:attribute:: Image.height
:type: int
Image height, in pixels.
.. py:attribute:: Image.palette
:type: Optional[PIL.ImagePalette.ImagePalette]
Colour palette table, if any. If mode is "P" or "PA", this should be an
instance of the :py:class:`~PIL.ImagePalette.ImagePalette` class.
Otherwise, it should be set to :data:`None`.
.. py:attribute:: Image.info
:type: dict
A dictionary holding data associated with the image. This dictionary is
used by file handlers to pass on various non-image information read from
the file. See documentation for the various file handlers for details.
Most methods ignore the dictionary when returning new images; since the
keys are not standardized, it’s not possible for a method to know if the
operation affects the dictionary. If you need the information later on,
keep a reference to the info dictionary returned from the open method.
Unless noted elsewhere, this dictionary does not affect saving files.
.. py:attribute:: Image.is_animated
:type: bool
``True`` if this image has more than one frame, or ``False`` otherwise.
This attribute is only defined by image plugins that support animated images.
Plugins may leave this attribute undefined if they don't support loading
animated images, even if the given format supports animated images.
Given that this attribute is not present for all images use
``getattr(image, "is_animated", False)`` to check if Pillow is aware of multiple
frames in an image regardless of its format.
.. seealso:: :attr:`~Image.n_frames`, :func:`~Image.seek` and :func:`~Image.tell`
.. py:attribute:: Image.n_frames
:type: int
The number of frames in this image.
This attribute is only defined by image plugins that support animated images.
Plugins may leave this attribute undefined if they don't support loading
animated images, even if the given format supports animated images.
Given that this attribute is not present for all images use
``getattr(image, "n_frames", 1)`` to check the number of frames that Pillow is
aware of in an image regardless of its format.
.. seealso:: :attr:`~Image.is_animated`, :func:`~Image.seek` and :func:`~Image.tell`
Classes
-------
.. autoclass:: PIL.Image.Exif
:members:
:undoc-members:
:show-inheritance:
.. autoclass:: PIL.Image.ImagePointHandler
.. autoclass:: PIL.Image.ImageTransformHandler
Constants
---------
.. data:: NONE
.. data:: MAX_IMAGE_PIXELS
Set to 89,478,485, approximately 0.25GB for a 24-bit (3 bpp) image.
See :py:meth:`~PIL.Image.open` for more information about how this is used.
Transpose methods
^^^^^^^^^^^^^^^^^
Used to specify the :meth:`Image.transpose` method to use.
.. autoclass:: Transpose
:members:
:undoc-members:
Transform methods
^^^^^^^^^^^^^^^^^
Used to specify the :meth:`Image.transform` method to use.
.. py:class:: Transform
.. py:attribute:: AFFINE
Affine transform
.. py:attribute:: EXTENT
Cut out a rectangular subregion
.. py:attribute:: PERSPECTIVE
Perspective transform
.. py:attribute:: QUAD
Map a quadrilateral to a rectangle
.. py:attribute:: MESH
Map a number of source quadrilaterals in one operation
Resampling filters
^^^^^^^^^^^^^^^^^^
See :ref:`concept-filters` for details.
.. autoclass:: Resampling
:members:
:undoc-members:
:noindex:
Some deprecated filters are also available under the following names:
.. data:: NONE
:noindex:
:value: Resampling.NEAREST
.. data:: LINEAR
:value: Resampling.BILINEAR
.. data:: CUBIC
:value: Resampling.BICUBIC
.. data:: ANTIALIAS
:value: Resampling.LANCZOS
Dither modes
^^^^^^^^^^^^
Used to specify the dithering method to use for the
:meth:`~Image.convert` and :meth:`~Image.quantize` methods.
.. py:class:: Dither
.. py:attribute:: NONE
No dither
.. py:attribute:: ORDERED
Not implemented
.. py:attribute:: RASTERIZE
Not implemented
.. py:attribute:: FLOYDSTEINBERG
Floyd-Steinberg dither
Palettes
^^^^^^^^
Used to specify the pallete to use for the :meth:`~Image.convert` method.
.. autoclass:: Palette
:members:
:undoc-members:
Quantization methods
^^^^^^^^^^^^^^^^^^^^
Used to specify the quantization method to use for the :meth:`~Image.quantize` method.
.. py:class:: Quantize
.. py:attribute:: MEDIANCUT
Median cut. Default method, except for RGBA images. This method does not support
RGBA images.
.. py:attribute:: MAXCOVERAGE
Maximum coverage. This method does not support RGBA images.
.. py:attribute:: FASTOCTREE
Fast octree. Default method for RGBA images.
.. py:attribute:: LIBIMAGEQUANT
libimagequant
Check support using :py:func:`PIL.features.check_feature` with
``feature="libimagequant"``.
Reference in New Issue View Git Blame Copy Permalink