PIL.Image 源代码
#
# The Python Imaging Library.
# $Id$
#
# the Image class wrapper
#
# partial release history:
# 1995-09-09 fl Created
# 1996-03-11 fl PIL release 0.0 (proof of concept)
# 1996-04-30 fl PIL release 0.1b1
# 1999-07-28 fl PIL release 1.0 final
# 2000-06-07 fl PIL release 1.1
# 2000-10-20 fl PIL release 1.1.1
# 2001-05-07 fl PIL release 1.1.2
# 2002-03-15 fl PIL release 1.1.3
# 2003-05-10 fl PIL release 1.1.4
# 2005-03-28 fl PIL release 1.1.5
# 2006-12-02 fl PIL release 1.1.6
# 2009-11-15 fl PIL release 1.1.7
#
# Copyright (c) 1997-2009 by Secret Labs AB. All rights reserved.
# Copyright (c) 1995-2009 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
import atexit
import builtins
import io
import logging
import math
import numbers
import os
import re
import struct
import sys
import tempfile
import warnings
from collections.abc import Callable, MutableMapping
from pathlib import Path
try:
import defusedxml.ElementTree as ElementTree
except ImportError:
ElementTree = None
# VERSION was removed in Pillow 6.0.0.
# PILLOW_VERSION is deprecated and will be removed in a future release.
# Use __version__ instead.
from . import (
ImageMode,
TiffTags,
UnidentifiedImageError,
__version__,
_plugins,
_raise_version_warning,
)
from ._binary import i32le
from ._util import deferred_error, isPath
if sys.version_info >= (3, 7):
def __getattr__(name):
if name == "PILLOW_VERSION":
_raise_version_warning()
return __version__
else:
categories = {"NORMAL": 0, "SEQUENCE": 1, "CONTAINER": 2}
if name in categories:
warnings.warn(
"Image categories are deprecated and will be removed in Pillow 10 "
"(2023-01-02). Use is_animated instead.",
DeprecationWarning,
stacklevel=2,
)
return categories[name]
raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
else:
from . import PILLOW_VERSION
# Silence warning
assert PILLOW_VERSION
# categories
NORMAL = 0
SEQUENCE = 1
CONTAINER = 2
logger = logging.getLogger(__name__)
class DecompressionBombWarning(RuntimeWarning):
pass
class DecompressionBombError(Exception):
pass
# Limit to around a quarter gigabyte for a 24-bit (3 bpp) image
MAX_IMAGE_PIXELS = int(1024 * 1024 * 1024 // 4 // 3)
try:
# If the _imaging C module is not present, Pillow will not load.
# Note that other modules should not refer to _imaging directly;
# import Image and use the Image.core variable instead.
# Also note that Image.core is not a publicly documented interface,
# and should be considered private and subject to change.
from . import _imaging as core
if __version__ != getattr(core, "PILLOW_VERSION", None):
raise ImportError(
"The _imaging extension was built for another version of Pillow or PIL:\n"
f"Core version: {getattr(core, 'PILLOW_VERSION', None)}\n"
f"Pillow version: {__version__}"
)
except ImportError as v:
core = deferred_error(ImportError("The _imaging C module is not installed."))
# Explanations for ways that we know we might have an import error
if str(v).startswith("Module use of python"):
# The _imaging C module is present, but not compiled for
# the right version (windows only). Print a warning, if
# possible.
warnings.warn(
"The _imaging extension was built for another version of Python.",
RuntimeWarning,
)
elif str(v).startswith("The _imaging extension"):
warnings.warn(str(v), RuntimeWarning)
# Fail here anyway. Don't let people run with a mostly broken Pillow.
# see docs/porting.rst
raise
# works everywhere, win for pypy, not cpython
USE_CFFI_ACCESS = hasattr(sys, "pypy_version_info")
try:
import cffi
except ImportError:
cffi = None
def isImageType(t):
"""
Checks if an object is an image object.
.. warning::
This function is for internal use only.
:param t: object to check if it's an image
:returns: True if the object is an image
"""
return hasattr(t, "im")
#
# Constants
NONE = 0
# transpose
FLIP_LEFT_RIGHT = 0
FLIP_TOP_BOTTOM = 1
ROTATE_90 = 2
ROTATE_180 = 3
ROTATE_270 = 4
TRANSPOSE = 5
TRANSVERSE = 6
# transforms (also defined in Imaging.h)
AFFINE = 0
EXTENT = 1
PERSPECTIVE = 2
QUAD = 3
MESH = 4
# resampling filters (also defined in Imaging.h)
NEAREST = NONE = 0
BOX = 4
BILINEAR = LINEAR = 2
HAMMING = 5
BICUBIC = CUBIC = 3
LANCZOS = ANTIALIAS = 1
_filters_support = {BOX: 0.5, BILINEAR: 1.0, HAMMING: 1.0, BICUBIC: 2.0, LANCZOS: 3.0}
# dithers
NEAREST = NONE = 0
ORDERED = 1 # Not yet implemented
RASTERIZE = 2 # Not yet implemented
FLOYDSTEINBERG = 3 # default
# palettes/quantizers
WEB = 0
ADAPTIVE = 1
MEDIANCUT = 0
MAXCOVERAGE = 1
FASTOCTREE = 2
LIBIMAGEQUANT = 3
if hasattr(core, "DEFAULT_STRATEGY"):
DEFAULT_STRATEGY = core.DEFAULT_STRATEGY
FILTERED = core.FILTERED
HUFFMAN_ONLY = core.HUFFMAN_ONLY
RLE = core.RLE
FIXED = core.FIXED
# --------------------------------------------------------------------
# Registries
ID = []
OPEN = {}
MIME = {}
SAVE = {}
SAVE_ALL = {}
EXTENSION = {}
DECODERS = {}
ENCODERS = {}
# --------------------------------------------------------------------
# Modes
if sys.byteorder == "little":
_ENDIAN = "<"
else:
_ENDIAN = ">"
_MODE_CONV = {
# official modes
"1": ("|b1", None), # Bits need to be extended to bytes
"L": ("|u1", None),
"LA": ("|u1", 2),
"I": (_ENDIAN + "i4", None),
"F": (_ENDIAN + "f4", None),
"P": ("|u1", None),
"RGB": ("|u1", 3),
"RGBX": ("|u1", 4),
"RGBA": ("|u1", 4),
"CMYK": ("|u1", 4),
"YCbCr": ("|u1", 3),
"LAB": ("|u1", 3), # UNDONE - unsigned |u1i1i1
"HSV": ("|u1", 3),
# I;16 == I;16L, and I;32 == I;32L
"I;16": ("<u2", None),
"I;16B": (">u2", None),
"I;16L": ("<u2", None),
"I;16S": ("<i2", None),
"I;16BS": (">i2", None),
"I;16LS": ("<i2", None),
"I;32": ("<u4", None),
"I;32B": (">u4", None),
"I;32L": ("<u4", None),
"I;32S": ("<i4", None),
"I;32BS": (">i4", None),
"I;32LS": ("<i4", None),
}
def _conv_type_shape(im):
typ, extra = _MODE_CONV[im.mode]
if extra is None:
return (im.size[1], im.size[0]), typ
else:
return (im.size[1], im.size[0], extra), typ
MODES = ["1", "CMYK", "F", "HSV", "I", "L", "LAB", "P", "RGB", "RGBA", "RGBX", "YCbCr"]
# raw modes that may be memory mapped. NOTE: if you change this, you
# may have to modify the stride calculation in map.c too!
_MAPMODES = ("L", "P", "RGBX", "RGBA", "CMYK", "I;16", "I;16L", "I;16B")
def getmodebase(mode):
"""
Gets the "base" mode for given mode. This function returns "L" for
images that contain grayscale data, and "RGB" for images that
contain color data.
:param mode: Input mode.
:returns: "L" or "RGB".
:exception KeyError: If the input mode was not a standard mode.
"""
return ImageMode.getmode(mode).basemode
def getmodetype(mode):
"""
Gets the storage type mode. Given a mode, this function returns a
single-layer mode suitable for storing individual bands.
:param mode: Input mode.
:returns: "L", "I", or "F".
:exception KeyError: If the input mode was not a standard mode.
"""
return ImageMode.getmode(mode).basetype
def getmodebandnames(mode):
"""
Gets a list of individual band names. Given a mode, this function returns
a tuple containing the names of individual bands (use
:py:method:`~PIL.Image.getmodetype` to get the mode used to store each
individual band.
:param mode: Input mode.
:returns: A tuple containing band names. The length of the tuple
gives the number of bands in an image of the given mode.
:exception KeyError: If the input mode was not a standard mode.
"""
return ImageMode.getmode(mode).bands
def getmodebands(mode):
"""
Gets the number of individual bands for this mode.
:param mode: Input mode.
:returns: The number of bands in this mode.
:exception KeyError: If the input mode was not a standard mode.
"""
return len(ImageMode.getmode(mode).bands)
# --------------------------------------------------------------------
# Helpers
_initialized = 0
def preinit():
"""Explicitly load standard file format drivers."""
global _initialized
if _initialized >= 1:
return
try:
from . import BmpImagePlugin
assert BmpImagePlugin
except ImportError:
pass
try:
from . import GifImagePlugin
assert GifImagePlugin
except ImportError:
pass
try:
from . import JpegImagePlugin
assert JpegImagePlugin
except ImportError:
pass
try:
from . import PpmImagePlugin
assert PpmImagePlugin
except ImportError:
pass
try:
from . import PngImagePlugin
assert PngImagePlugin
except ImportError:
pass
# try:
# import TiffImagePlugin
# assert TiffImagePlugin
# except ImportError:
# pass
_initialized = 1
def init():
"""
Explicitly initializes the Python Imaging Library. This function
loads all available file format drivers.
"""
global _initialized
if _initialized >= 2:
return 0
for plugin in _plugins:
try:
logger.debug("Importing %s", plugin)
__import__(f"PIL.{plugin}", globals(), locals(), [])
except ImportError as e:
logger.debug("Image: failed to import %s: %s", plugin, e)
if OPEN or SAVE:
_initialized = 2
return 1
# --------------------------------------------------------------------
# Codec factories (used by tobytes/frombytes and ImageFile.load)
def _getdecoder(mode, decoder_name, args, extra=()):
# tweak arguments
if args is None:
args = ()
elif not isinstance(args, tuple):
args = (args,)
try:
decoder = DECODERS[decoder_name]
except KeyError:
pass
else:
return decoder(mode, *args + extra)
try:
# get decoder
decoder = getattr(core, decoder_name + "_decoder")
except AttributeError as e:
raise OSError(f"decoder {decoder_name} not available") from e
return decoder(mode, *args + extra)
def _getencoder(mode, encoder_name, args, extra=()):
# tweak arguments
if args is None:
args = ()
elif not isinstance(args, tuple):
args = (args,)
try:
encoder = ENCODERS[encoder_name]
except KeyError:
pass
else:
return encoder(mode, *args + extra)
try:
# get encoder
encoder = getattr(core, encoder_name + "_encoder")
except AttributeError as e:
raise OSError(f"encoder {encoder_name} not available") from e
return encoder(mode, *args + extra)
# --------------------------------------------------------------------
# Simple expression analyzer
def coerce_e(value):
return value if isinstance(value, _E) else _E(value)
class _E:
def __init__(self, data):
self.data = data
def __add__(self, other):
return _E((self.data, "__add__", coerce_e(other).data))
def __mul__(self, other):
return _E((self.data, "__mul__", coerce_e(other).data))
def _getscaleoffset(expr):
stub = ["stub"]
data = expr(_E(stub)).data
try:
(a, b, c) = data # simplified syntax
if a is stub and b == "__mul__" and isinstance(c, numbers.Number):
return c, 0.0
if a is stub and b == "__add__" and isinstance(c, numbers.Number):
return 1.0, c
except TypeError:
pass
try:
((a, b, c), d, e) = data # full syntax
if (
a is stub
and b == "__mul__"
and isinstance(c, numbers.Number)
and d == "__add__"
and isinstance(e, numbers.Number)
):
return c, e
except TypeError:
pass
raise ValueError("illegal expression")
# --------------------------------------------------------------------
# Implementation wrapper
[文档]class Image:
"""
This class represents an image object. To create
:py:class:`~PIL.Image.Image` objects, use the appropriate factory
functions. There's hardly ever any reason to call the Image constructor
directly.
* :py:func:`~PIL.Image.open`
* :py:func:`~PIL.Image.new`
* :py:func:`~PIL.Image.frombytes`
"""
format = None
format_description = None
_close_exclusive_fp_after_loading = True
def __init__(self):
# FIXME: take "new" parameters / other image?
# FIXME: turn mode and size into delegating properties?
self.im = None
self.mode = ""
self._size = (0, 0)
self.palette = None
self.info = {}
self._category = 0
self.readonly = 0
self.pyaccess = None
self._exif = None
def __getattr__(self, name):
if name == "category":
warnings.warn(
"Image categories are deprecated and will be removed in Pillow 10 "
"(2023-01-02). Use is_animated instead.",
DeprecationWarning,
stacklevel=2,
)
return self._category
raise AttributeError(name)
@property
def width(self):
return self.size[0]
@property
def height(self):
return self.size[1]
@property
def size(self):
return self._size
def _new(self, im):
new = Image()
new.im = im
new.mode = im.mode
new._size = im.size
if im.mode in ("P", "PA"):
if self.palette:
new.palette = self.palette.copy()
else:
from . import ImagePalette
new.palette = ImagePalette.ImagePalette()
new.info = self.info.copy()
return new
# Context manager support
def __enter__(self):
return self
def __exit__(self, *args):
if hasattr(self, "fp") and getattr(self, "_exclusive_fp", False):
if hasattr(self, "_close__fp"):
self._close__fp()
if self.fp:
self.fp.close()
self.fp = None
[文档] def close(self):
"""
Closes the file pointer, if possible.
This operation will destroy the image core and release its memory.
The image data will be unusable afterward.
This function is required to close images that have multiple frames or
have not had their file read and closed by the
:py:meth:`~PIL.Image.Image.load` method. See :ref:`file-handling` for
more information.
"""
try:
if hasattr(self, "_close__fp"):
self._close__fp()
if self.fp:
self.fp.close()
self.fp = None
except Exception as msg:
logger.debug("Error closing: %s", msg)
if getattr(self, "map", None):
self.map = None
# Instead of simply setting to None, we're setting up a
# deferred error that will better explain that the core image
# object is gone.
self.im = deferred_error(ValueError("Operation on closed image"))
def _copy(self):
self.load()
self.im = self.im.copy()
self.pyaccess = None
self.readonly = 0
def _ensure_mutable(self):
if self.readonly:
self._copy()
else:
self.load()
def _dump(self, file=None, format=None, **options):
suffix = ""
if format:
suffix = "." + format
if not file:
f, filename = tempfile.mkstemp(suffix)
os.close(f)
else:
filename = file
if not filename.endswith(suffix):
filename = filename + suffix
self.load()
if not format or format == "PPM":
self.im.save_ppm(filename)
else:
self.save(filename, format, **options)
return filename
def __eq__(self, other):
return (
self.__class__ is other.__class__
and self.mode == other.mode
and self.size == other.size
and self.info == other.info
and self._category == other._category
and self.readonly == other.readonly
and self.getpalette() == other.getpalette()
and self.tobytes() == other.tobytes()
)
def __repr__(self):
return "<%s.%s image mode=%s size=%dx%d at 0x%X>" % (
self.__class__.__module__,
self.__class__.__name__,
self.mode,
self.size[0],
self.size[1],
id(self),
)
def _repr_png_(self):
"""iPython display hook support
:returns: png version of the image as bytes
"""
b = io.BytesIO()
try:
self.save(b, "PNG")
except Exception as e:
raise ValueError("Could not save to PNG for display") from e
return b.getvalue()
def __array__(self, dtype=None):
# numpy array interface support
import numpy as np
new = {}
shape, typestr = _conv_type_shape(self)
new["shape"] = shape
new["typestr"] = typestr
new["version"] = 3
if self.mode == "1":
# Binary images need to be extended from bits to bytes
# See: https://github.com/python-pillow/Pillow/issues/350
new["data"] = self.tobytes("raw", "L")
else:
new["data"] = self.tobytes()
class ArrayData:
__array_interface__ = new
return np.array(ArrayData(), dtype)
def __getstate__(self):
return [self.info, self.mode, self.size, self.getpalette(), self.tobytes()]
def __setstate__(self, state):
Image.__init__(self)
self.tile = []
info, mode, size, palette, data = state
self.info = info
self.mode = mode
self._size = size
self.im = core.new(mode, size)
if mode in ("L", "LA", "P", "PA") and palette:
self.putpalette(palette)
self.frombytes(data)
[文档] def tobytes(self, encoder_name="raw", *args):
"""
Return image as a bytes object.
.. warning::
This method returns the raw image data from the internal
storage. For compressed image data (e.g. PNG, JPEG) use
:meth:`~.save`, with a BytesIO parameter for in-memory
data.
:param encoder_name: What encoder to use. The default is to
use the standard "raw" encoder.
:param args: Extra arguments to the encoder.
:returns: A :py:class:`bytes` object.
"""
# may pass tuple instead of argument list
if len(args) == 1 and isinstance(args[0], tuple):
args = args[0]
if encoder_name == "raw" and args == ():
args = self.mode
self.load()
# unpack data
e = _getencoder(self.mode, encoder_name, args)
e.setimage(self.im)
bufsize = max(65536, self.size[0] * 4) # see RawEncode.c
data = []
while True:
l, s, d = e.encode(bufsize)
data.append(d)
if s:
break
if s < 0:
raise RuntimeError(f"encoder error {s} in tobytes")
return b"".join(data)
[文档] def tobitmap(self, name="image"):
"""
Returns the image converted to an X11 bitmap.
.. note:: This method only works for mode "1" images.
:param name: The name prefix to use for the bitmap variables.
:returns: A string containing an X11 bitmap.
:raises ValueError: If the mode is not "1"
"""
self.load()
if self.mode != "1":
raise ValueError("not a bitmap")
data = self.tobytes("xbm")
return b"".join(
[
f"#define {name}_width {self.size[0]}\n".encode("ascii"),
f"#define {name}_height {self.size[1]}\n".encode("ascii"),
f"static char {name}_bits[] = {{\n".encode("ascii"),
data,
b"};",
]
)
[文档] def frombytes(self, data, decoder_name="raw", *args):
"""
Loads this image with pixel data from a bytes object.
This method is similar to the :py:func:`~PIL.Image.frombytes` function,
but loads data into this image instead of creating a new image object.
"""
# may pass tuple instead of argument list
if len(args) == 1 and isinstance(args[0], tuple):
args = args[0]
# default format
if decoder_name == "raw" and args == ():
args = self.mode
# unpack data
d = _getdecoder(self.mode, decoder_name, args)
d.setimage(self.im)
s = d.decode(data)
if s[0] >= 0:
raise ValueError("not enough image data")
if s[1] != 0:
raise ValueError("cannot decode image data")
[文档] def load(self):
"""
Allocates storage for the image and loads the pixel data. In
normal cases, you don't need to call this method, since the
Image class automatically loads an opened image when it is
accessed for the first time.
If the file associated with the image was opened by Pillow, then this
method will close it. The exception to this is if the image has
multiple frames, in which case the file will be left open for seek
operations. See :ref:`file-handling` for more information.
:returns: An image access object.
:rtype: :ref:`PixelAccess` or :py:class:`PIL.PyAccess`
"""
if self.im and self.palette and self.palette.dirty:
# realize palette
mode, arr = self.palette.getdata()
if mode == "RGBA":
mode = "RGB"
self.info["transparency"] = arr[3::4]
arr = bytes(
value for (index, value) in enumerate(arr) if index % 4 != 3
)
palette_length = self.im.putpalette(mode, arr)
self.palette.dirty = 0
self.palette.rawmode = None
if "transparency" in self.info and mode in ("RGBA", "LA", "PA"):
if isinstance(self.info["transparency"], int):
self.im.putpalettealpha(self.info["transparency"], 0)
else:
self.im.putpalettealphas(self.info["transparency"])
self.palette.mode = "RGBA"
else:
self.palette.mode = "RGB"
self.palette.palette = self.im.getpalette()[: palette_length * 3]
if self.im:
if cffi and USE_CFFI_ACCESS:
if self.pyaccess:
return self.pyaccess
from . import PyAccess
self.pyaccess = PyAccess.new(self, self.readonly)
if self.pyaccess:
return self.pyaccess
return self.im.pixel_access(self.readonly)
[文档] def verify(self):
"""
Verifies the contents of a file. For data read from a file, this
method attempts to determine if the file is broken, without
actually decoding the image data. If this method finds any
problems, it raises suitable exceptions. If you need to load
the image after using this method, you must reopen the image
file.
"""
pass
[文档] def convert(self, mode=None, matrix=None, dither=None, palette=WEB, colors=256):
"""
Returns a converted copy of this image. For the "P" mode, this
method translates pixels through the palette. If mode is
omitted, a mode is chosen so that all information in the image
and the palette can be represented without a palette.
The current version supports all possible conversions between
"L", "RGB" and "CMYK." The ``matrix`` argument only supports "L"
and "RGB".
When translating a color image to greyscale (mode "L"),
the library uses the ITU-R 601-2 luma transform::
L = R * 299/1000 + G * 587/1000 + B * 114/1000
The default method of converting a greyscale ("L") or "RGB"
image into a bilevel (mode "1") image uses Floyd-Steinberg
dither to approximate the original image luminosity levels. If
dither is :data:`NONE`, all values larger than 127 are set to 255 (white),
all other values to 0 (black). To use other thresholds, use the
:py:meth:`~PIL.Image.Image.point` method.
When converting from "RGBA" to "P" without a ``matrix`` argument,
this passes the operation to :py:meth:`~PIL.Image.Image.quantize`,
and ``dither`` and ``palette`` are ignored.
:param mode: The requested mode. See: :ref:`concept-modes`.
:param matrix: An optional conversion matrix. If given, this
should be 4- or 12-tuple containing floating point values.
:param dither: Dithering method, used when converting from
mode "RGB" to "P" or from "RGB" or "L" to "1".
Available methods are :data:`NONE` or :data:`FLOYDSTEINBERG` (default).
Note that this is not used when ``matrix`` is supplied.
:param palette: Palette to use when converting from mode "RGB"
to "P". Available palettes are :data:`WEB` or :data:`ADAPTIVE`.
:param colors: Number of colors to use for the :data:`ADAPTIVE` palette.
Defaults to 256.
:rtype: :py:class:`~PIL.Image.Image`
:returns: An :py:class:`~PIL.Image.Image` object.
"""
self.load()
has_transparency = self.info.get("transparency") is not None
if not mode and self.mode == "P":
# determine default mode
if self.palette:
mode = self.palette.mode
else:
mode = "RGB"
if mode == "RGB" and has_transparency:
mode = "RGBA"
if not mode or (mode == self.mode and not matrix):
return self.copy()
if matrix:
# matrix conversion
if mode not in ("L", "RGB"):
raise ValueError("illegal conversion")
im = self.im.convert_matrix(mode, matrix)
new = self._new(im)
if has_transparency and self.im.bands == 3:
transparency = new.info["transparency"]
def convert_transparency(m, v):
v = m[0] * v[0] + m[1] * v[1] + m[2] * v[2] + m[3] * 0.5
return max(0, min(255, int(v)))
if mode == "L":
transparency = convert_transparency(matrix, transparency)
elif len(mode) == 3:
transparency = tuple(
[
convert_transparency(
matrix[i * 4 : i * 4 + 4], transparency
)
for i in range(0, len(transparency))
]
)
new.info["transparency"] = transparency
return new
if mode == "P" and self.mode == "RGBA":
return self.quantize(colors)
trns = None
delete_trns = False
# transparency handling
if has_transparency:
if self.mode in ("1", "L", "I", "RGB") and mode == "RGBA":
# Use transparent conversion to promote from transparent
# color to an alpha channel.
new_im = self._new(
self.im.convert_transparent(mode, self.info["transparency"])
)
del new_im.info["transparency"]
return new_im
elif self.mode in ("L", "RGB", "P") and mode in ("L", "RGB", "P"):
t = self.info["transparency"]
if isinstance(t, bytes):
# Dragons. This can't be represented by a single color
warnings.warn(
"Palette images with Transparency expressed in bytes should be "
"converted to RGBA images"
)
delete_trns = True
else:
# get the new transparency color.
# use existing conversions
trns_im = Image()._new(core.new(self.mode, (1, 1)))
if self.mode == "P":
trns_im.putpalette(self.palette)
if isinstance(t, tuple):
err = "Couldn't allocate a palette color for transparency"
try:
t = trns_im.palette.getcolor(t, self)
except ValueError as e:
if str(e) == "cannot allocate more than 256 colors":
# If all 256 colors are in use,
# then there is no need for transparency
t = None
else:
raise ValueError(err) from e
if t is None:
trns = None
else:
trns_im.putpixel((0, 0), t)
if mode in ("L", "RGB"):
trns_im = trns_im.convert(mode)
else:
# can't just retrieve the palette number, got to do it
# after quantization.
trns_im = trns_im.convert("RGB")
trns = trns_im.getpixel((0, 0))
elif self.mode == "P" and mode in ("LA", "PA", "RGBA"):
t = self.info["transparency"]
delete_trns = True
if isinstance(t, bytes):
self.im.putpalettealphas(t)
elif isinstance(t, int):
self.im.putpalettealpha(t, 0)
else:
raise ValueError("Transparency for P mode should be bytes or int")
if mode == "P" and palette == ADAPTIVE:
im = self.im.quantize(colors)
new = self._new(im)
from . import ImagePalette
new.palette = ImagePalette.ImagePalette("RGB", new.im.getpalette("RGB"))
if delete_trns:
# This could possibly happen if we requantize to fewer colors.
# The transparency would be totally off in that case.
del new.info["transparency"]
if trns is not None:
try:
new.info["transparency"] = new.palette.getcolor(trns, new)
except Exception:
# if we can't make a transparent color, don't leave the old
# transparency hanging around to mess us up.
del new.info["transparency"]
warnings.warn("Couldn't allocate palette entry for transparency")
return new
# colorspace conversion
if dither is None:
dither = FLOYDSTEINBERG
try:
im = self.im.convert(mode, dither)
except ValueError:
try:
# normalize source image and try again
im = self.im.convert(getmodebase(self.mode))
im = im.convert(mode, dither)
except KeyError as e:
raise ValueError("illegal conversion") from e
new_im = self._new(im)
if mode == "P" and palette != ADAPTIVE:
from . import ImagePalette
new_im.palette = ImagePalette.ImagePalette("RGB", list(range(256)) * 3)
if delete_trns:
# crash fail if we leave a bytes transparency in an rgb/l mode.
del new_im.info["transparency"]
if trns is not None:
if new_im.mode == "P":
try:
new_im.info["transparency"] = new_im.palette.getcolor(trns, new_im)
except ValueError as e:
del new_im.info["transparency"]
if str(e) != "cannot allocate more than 256 colors":
# If all 256 colors are in use,
# then there is no need for transparency
warnings.warn(
"Couldn't allocate palette entry for transparency"
)
else:
new_im.info["transparency"] = trns
return new_im
[文档] def quantize(self, colors=256, method=None, kmeans=0, palette=None, dither=1):
"""
Convert the image to 'P' mode with the specified number
of colors.
:param colors: The desired number of colors, <= 256
:param method: :data:`MEDIANCUT` (median cut),
:data:`MAXCOVERAGE` (maximum coverage),
:data:`FASTOCTREE` (fast octree),
:data:`LIBIMAGEQUANT` (libimagequant; check support using
:py:func:`PIL.features.check_feature`
with ``feature="libimagequant"``).
By default, :data:`MEDIANCUT` will be used.
The exception to this is RGBA images. :data:`MEDIANCUT` and
:data:`MAXCOVERAGE` do not support RGBA images, so
:data:`FASTOCTREE` is used by default instead.
:param kmeans: Integer
:param palette: Quantize to the palette of given
:py:class:`PIL.Image.Image`.
:param dither: Dithering method, used when converting from
mode "RGB" to "P" or from "RGB" or "L" to "1".
Available methods are :data:`NONE` or :data:`FLOYDSTEINBERG` (default).
Default: 1 (legacy setting)
:returns: A new image
"""
self.load()
if method is None:
# defaults:
method = MEDIANCUT
if self.mode == "RGBA":
method = FASTOCTREE
if self.mode == "RGBA" and method not in (FASTOCTREE, LIBIMAGEQUANT):
# Caller specified an invalid mode.
raise ValueError(
"Fast Octree (method == 2) and libimagequant (method == 3) "
"are the only valid methods for quantizing RGBA images"
)
if palette:
# use palette from reference image
palette.load()
if palette.mode != "P":
raise ValueError("bad mode for palette image")
if self.mode != "RGB" and self.mode != "L":
raise ValueError(
"only RGB or L mode images can be quantized to a palette"
)
im = self.im.convert("P", dither, palette.im)
new_im = self._new(im)
new_im.palette = palette.palette.copy()
return new_im
im = self._new(self.im.quantize(colors, method, kmeans))
from . import ImagePalette
mode = im.im.getpalettemode()
im.palette = ImagePalette.ImagePalette(mode, im.im.getpalette(mode, mode))
return im
[文档] def copy(self):
"""
Copies this image. Use this method if you wish to paste things
into an image, but still retain the original.
:rtype: :py:class:`~PIL.Image.Image`
:returns: An :py:class:`~PIL.Image.Image` object.
"""
self.load()
return self._new(self.im.copy())
__copy__ = copy
[文档] def crop(self, box=None):
"""
Returns a rectangular region from this image. The box is a
4-tuple defining the left, upper, right, and lower pixel
coordinate. See :ref:`coordinate-system`.
Note: Prior to Pillow 3.4.0, this was a lazy operation.
:param box: The crop rectangle, as a (left, upper, right, lower)-tuple.
:rtype: :py:class:`~PIL.Image.Image`
:returns: An :py:class:`~PIL.Image.Image` object.
"""
if box is None:
return self.copy()
self.load()
return self._new(self._crop(self.im, box))
def _crop(self, im, box):
"""
Returns a rectangular region from the core image object im.
This is equivalent to calling im.crop((x0, y0, x1, y1)), but
includes additional sanity checks.
:param im: a core image object
:param box: The crop rectangle, as a (left, upper, right, lower)-tuple.
:returns: A core image object.
"""
x0, y0, x1, y1 = map(int, map(round, box))
absolute_values = (abs(x1 - x0), abs(y1 - y0))
_decompression_bomb_check(absolute_values)
return im.crop((x0, y0, x1, y1))
[文档] def draft(self, mode, size):
"""
Configures the image file loader so it returns a version of the
image that as closely as possible matches the given mode and
size. For example, you can use this method to convert a color
JPEG to greyscale while loading it.
If any changes are made, returns a tuple with the chosen ``mode`` and
``box`` with coordinates of the original image within the altered one.
Note that this method modifies the :py:class:`~PIL.Image.Image` object
in place. If the image has already been loaded, this method has no
effect.
Note: This method is not implemented for most images. It is
currently implemented only for JPEG and MPO images.
:param mode: The requested mode.
:param size: The requested size.
"""
pass
def _expand(self, xmargin, ymargin=None):
if ymargin is None:
ymargin = xmargin
self.load()
return self._new(self.im.expand(xmargin, ymargin, 0))
[文档] def filter(self, filter):
"""
Filters this image using the given filter. For a list of
available filters, see the :py:mod:`~PIL.ImageFilter` module.
:param filter: Filter kernel.
:returns: An :py:class:`~PIL.Image.Image` object."""
from . import ImageFilter
self.load()
if isinstance(filter, Callable):
filter = filter()
if not hasattr(filter, "filter"):
raise TypeError(
"filter argument should be ImageFilter.Filter instance or class"
)
multiband = isinstance(filter, ImageFilter.MultibandFilter)
if self.im.bands == 1 or multiband:
return self._new(filter.filter(self.im))
ims = []
for c in range(self.im.bands):
ims.append(self._new(filter.filter(self.im.getband(c))))
return merge(self.mode, ims)
[文档] def getbands(self):
"""
Returns a tuple containing the name of each band in this image.
For example, ``getbands`` on an RGB image returns ("R", "G", "B").
:returns: A tuple containing band names.
:rtype: tuple
"""
return ImageMode.getmode(self.mode).bands
[文档] def getbbox(self):
"""
Calculates the bounding box of the non-zero regions in the
image.
:returns: The bounding box is returned as a 4-tuple defining the
left, upper, right, and lower pixel coordinate. See
:ref:`coordinate-system`. If the image is completely empty, this
method returns None.
"""
self.load()
return self.im.getbbox()
[文档] def getcolors(self, maxcolors=256):
"""
Returns a list of colors used in this image.
The colors will be in the image's mode. For example, an RGB image will
return a tuple of (red, green, blue) color values, and a P image will
return the index of the color in the palette.
:param maxcolors: Maximum number of colors. If this number is
exceeded, this method returns None. The default limit is
256 colors.
:returns: An unsorted list of (count, pixel) values.
"""
self.load()
if self.mode in ("1", "L", "P"):
h = self.im.histogram()
out = []
for i in range(256):
if h[i]:
out.append((h[i], i))
if len(out) > maxcolors:
return None
return out
return self.im.getcolors(maxcolors)
[文档] def getdata(self, band=None):
"""
Returns the contents of this image as a sequence object
containing pixel values. The sequence object is flattened, so
that values for line one follow directly after the values of
line zero, and so on.
Note that the sequence object returned by this method is an
internal PIL data type, which only supports certain sequence
operations. To convert it to an ordinary sequence (e.g. for
printing), use ``list(im.getdata())``.
:param band: What band to return. The default is to return
all bands. To return a single band, pass in the index
value (e.g. 0 to get the "R" band from an "RGB" image).
:returns: A sequence-like object.
"""
self.load()
if band is not None:
return self.im.getband(band)
return self.im # could be abused
[文档] def getextrema(self):
"""
Gets the the minimum and maximum pixel values for each band in
the image.
:returns: For a single-band image, a 2-tuple containing the
minimum and maximum pixel value. For a multi-band image,
a tuple containing one 2-tuple for each band.
"""
self.load()
if self.im.bands > 1:
extrema = []
for i in range(self.im.bands):
extrema.append(self.im.getband(i).getextrema())
return tuple(extrema)
return self.im.getextrema()
def _getxmp(self, xmp_tags):
def get_name(tag):
return tag.split("}")[1]
def get_value(element):
value = {get_name(k): v for k, v in element.attrib.items()}
children = list(element)
if children:
for child in children:
name = get_name(child.tag)
child_value = get_value(child)
if name in value:
if not isinstance(value[name], list):
value[name] = [value[name]]
value[name].append(child_value)
else:
value[name] = child_value
elif value:
if element.text:
value["text"] = element.text
else:
return element.text
return value
if ElementTree is None:
warnings.warn("XMP data cannot be read without defusedxml dependency")
return {}
else:
root = ElementTree.fromstring(xmp_tags)
return {get_name(root.tag): get_value(root)}
[文档] def getexif(self):
if self._exif is None:
self._exif = Exif()
exif_info = self.info.get("exif")
if exif_info is None:
if "Raw profile type exif" in self.info:
exif_info = bytes.fromhex(
"".join(self.info["Raw profile type exif"].split("\n")[3:])
)
elif hasattr(self, "tag_v2"):
self._exif.endian = self.tag_v2._endian
self._exif.load_from_fp(self.fp, self.tag_v2._offset)
if exif_info is not None:
self._exif.load(exif_info)
# XMP tags
if 0x0112 not in self._exif:
xmp_tags = self.info.get("XML:com.adobe.xmp")
if xmp_tags:
match = re.search(r'tiff:Orientation="([0-9])"', xmp_tags)
if match:
self._exif[0x0112] = int(match[1])
return self._exif
def getim(self):
"""
Returns a capsule that points to the internal image memory.
:returns: A capsule object.
"""
self.load()
return self.im.ptr
[文档] def getpalette(self):
"""
Returns the image palette as a list.
:returns: A list of color values [r, g, b, ...], or None if the
image has no palette.
"""
self.load()
try:
return list(self.im.getpalette())
except ValueError:
return None # no palette
[文档] def getpixel(self, xy):
"""
Returns the pixel value at a given position.
:param xy: The coordinate, given as (x, y). See
:ref:`coordinate-system`.
:returns: The pixel value. If the image is a multi-layer image,
this method returns a tuple.
"""
self.load()
if self.pyaccess:
return self.pyaccess.getpixel(xy)
return self.im.getpixel(xy)
[文档] def getprojection(self):
"""
Get projection to x and y axes
:returns: Two sequences, indicating where there are non-zero
pixels along the X-axis and the Y-axis, respectively.
"""
self.load()
x, y = self.im.getprojection()
return list(x), list(y)
[文档] def histogram(self, mask=None, extrema=None):
"""
Returns a histogram for the image. The histogram is returned as
a list of pixel counts, one for each pixel value in the source
image. If the image has more than one band, the histograms for
all bands are concatenated (for example, the histogram for an
"RGB" image contains 768 values).
A bilevel image (mode "1") is treated as a greyscale ("L") image
by this method.
If a mask is provided, the method returns a histogram for those
parts of the image where the mask image is non-zero. The mask
image must have the same size as the image, and be either a
bi-level image (mode "1") or a greyscale image ("L").
:param mask: An optional mask.
:param extrema: An optional tuple of manually-specified extrema.
:returns: A list containing pixel counts.
"""
self.load()
if mask:
mask.load()
return self.im.histogram((0, 0), mask.im)
if self.mode in ("I", "F"):
if extrema is None:
extrema = self.getextrema()
return self.im.histogram(extrema)
return self.im.histogram()
[文档] def entropy(self, mask=None, extrema=None):
"""
Calculates and returns the entropy for the image.
A bilevel image (mode "1") is treated as a greyscale ("L")
image by this method.
If a mask is provided, the method employs the histogram for
those parts of the image where the mask image is non-zero.
The mask image must have the same size as the image, and be
either a bi-level image (mode "1") or a greyscale image ("L").
:param mask: An optional mask.
:param extrema: An optional tuple of manually-specified extrema.
:returns: A float value representing the image entropy
"""
self.load()
if mask:
mask.load()
return self.im.entropy((0, 0), mask.im)
if self.mode in ("I", "F"):
if extrema is None:
extrema = self.getextrema()
return self.im.entropy(extrema)
return self.im.entropy()
[文档] def paste(self, im, box=None, mask=None):
"""
Pastes another image into this image. The box argument is either
a 2-tuple giving the upper left corner, a 4-tuple defining the
left, upper, right, and lower pixel coordinate, or None (same as
(0, 0)). See :ref:`coordinate-system`. If a 4-tuple is given, the size
of the pasted image must match the size of the region.
If the modes don't match, the pasted image is converted to the mode of
this image (see the :py:meth:`~PIL.Image.Image.convert` method for
details).
Instead of an image, the source can be a integer or tuple
containing pixel values. The method then fills the region
with the given color. When creating RGB images, you can
also use color strings as supported by the ImageColor module.
If a mask is given, this method updates only the regions
indicated by the mask. You can use either "1", "L" or "RGBA"
images (in the latter case, the alpha band is used as mask).
Where the mask is 255, the given image is copied as is. Where
the mask is 0, the current value is preserved. Intermediate
values will mix the two images together, including their alpha
channels if they have them.
See :py:meth:`~PIL.Image.Image.alpha_composite` if you want to
combine images with respect to their alpha channels.
:param im: Source image or pixel value (integer or tuple).
:param box: An optional 4-tuple giving the region to paste into.
If a 2-tuple is used instead, it's treated as the upper left
corner. If omitted or None, the source is pasted into the
upper left corner.
If an image is given as the second argument and there is no
third, the box defaults to (0, 0), and the second argument
is interpreted as a mask image.
:param mask: An optional mask image.
"""
if isImageType(box) and mask is None:
# abbreviated paste(im, mask) syntax
mask = box
box = None
if box is None:
box = (0, 0)
if len(box) == 2:
# upper left corner given; get size from image or mask
if isImageType(im):
size = im.size
elif isImageType(mask):
size = mask.size
else:
# FIXME: use self.size here?
raise ValueError("cannot determine region size; use 4-item box")
box += (box[0] + size[0], box[1] + size[1])
if isinstance(im, str):
from . import ImageColor
im = ImageColor.getcolor(im, self.mode)
elif isImageType(im):
im.load()
if self.mode != im.mode:
if self.mode != "RGB" or im.mode not in ("RGBA", "RGBa"):
# should use an adapter for this!
im = im.convert(self.mode)
im = im.im
self._ensure_mutable()
if mask:
mask.load()
self.im.paste(im, box, mask.im)
else:
self.im.paste(im, box)
[文档] def alpha_composite(self, im, dest=(0, 0), source=(0, 0)):
"""'In-place' analog of Image.alpha_composite. Composites an image
onto this image.
:param im: image to composite over this one
:param dest: Optional 2 tuple (left, top) specifying the upper
left corner in this (destination) image.
:param source: Optional 2 (left, top) tuple for the upper left
corner in the overlay source image, or 4 tuple (left, top, right,
bottom) for the bounds of the source rectangle
Performance Note: Not currently implemented in-place in the core layer.
"""
if not isinstance(source, (list, tuple)):
raise ValueError("Source must be a tuple")
if not isinstance(dest, (list, tuple)):
raise ValueError("Destination must be a tuple")
if not len(source) in (2, 4):
raise ValueError("Source must be a 2 or 4-tuple")
if not len(dest) == 2:
raise ValueError("Destination must be a 2-tuple")
if min(source) < 0:
raise ValueError("Source must be non-negative")
if len(source) == 2:
source = source + im.size
# over image, crop if it's not the whole thing.
if source == (0, 0) + im.size:
overlay = im
else:
overlay = im.crop(source)
# target for the paste
box = dest + (dest[0] + overlay.width, dest[1] + overlay.height)
# destination image. don't copy if we're using the whole image.
if box == (0, 0) + self.size:
background = self
else:
background = self.crop(box)
result = alpha_composite(background, overlay)
self.paste(result, box)
[文档] def point(self, lut, mode=None):
"""
Maps this image through a lookup table or function.
:param lut: A lookup table, containing 256 (or 65536 if
self.mode=="I" and mode == "L") values per band in the
image. A function can be used instead, it should take a
single argument. The function is called once for each
possible pixel value, and the resulting table is applied to
all bands of the image.
It may also be an :py:class:`~PIL.Image.ImagePointHandler`
object::
class Example(Image.ImagePointHandler):
def point(self, data):
# Return result
:param mode: Output mode (default is same as input). In the
current version, this can only be used if the source image
has mode "L" or "P", and the output has mode "1" or the
source image mode is "I" and the output mode is "L".
:returns: An :py:class:`~PIL.Image.Image` object.
"""
self.load()
if isinstance(lut, ImagePointHandler):
return lut.point(self)
if callable(lut):
# if it isn't a list, it should be a function
if self.mode in ("I", "I;16", "F"):
# check if the function can be used with point_transform
# UNDONE wiredfool -- I think this prevents us from ever doing
# a gamma function point transform on > 8bit images.
scale, offset = _getscaleoffset(lut)
return self._new(self.im.point_transform(scale, offset))
# for other modes, convert the function to a table
lut = [lut(i) for i in range(256)] * self.im.bands
if self.mode == "F":
# FIXME: _imaging returns a confusing error message for this case
raise ValueError("point operation not supported for this mode")
return self._new(self.im.point(lut, mode))
[文档] def putalpha(self, alpha):
"""
Adds or replaces the alpha layer in this image. If the image
does not have an alpha layer, it's converted to "LA" or "RGBA".
The new layer must be either "L" or "1".
:param alpha: The new alpha layer. This can either be an "L" or "1"
image having the same size as this image, or an integer or
other color value.
"""
self._ensure_mutable()
if self.mode not in ("LA", "PA", "RGBA"):
# attempt to promote self to a matching alpha mode
try:
mode = getmodebase(self.mode) + "A"
try:
self.im.setmode(mode)
except (AttributeError, ValueError) as e:
# do things the hard way
im = self.im.convert(mode)
if im.mode not in ("LA", "PA", "RGBA"):
raise ValueError from e # sanity check
self.im = im
self.pyaccess = None
self.mode = self.im.mode
except KeyError as e:
raise ValueError("illegal image mode") from e
if self.mode in ("LA", "PA"):
band = 1
else:
band = 3
if isImageType(alpha):
# alpha layer
if alpha.mode not in ("1", "L"):
raise ValueError("illegal image mode")
alpha.load()
if alpha.mode == "1":
alpha = alpha.convert("L")
else:
# constant alpha
try:
self.im.fillband(band, alpha)
except (AttributeError, ValueError):
# do things the hard way
alpha = new("L", self.size, alpha)
else:
return
self.im.putband(alpha.im, band)
[文档] def putdata(self, data, scale=1.0, offset=0.0):
"""
Copies pixel data to this image. This method copies data from a
sequence object into the image, starting at the upper left
corner (0, 0), and continuing until either the image or the
sequence ends. The scale and offset values are used to adjust
the sequence values: **pixel = value*scale + offset**.
:param data: A sequence object.
:param scale: An optional scale value. The default is 1.0.
:param offset: An optional offset value. The default is 0.0.
"""
self._ensure_mutable()
self.im.putdata(data, scale, offset)
[文档] def putpalette(self, data, rawmode="RGB"):
"""
Attaches a palette to this image. The image must be a "P", "PA", "L"
or "LA" image.
The palette sequence must contain at most 256 colors, made up of one
integer value for each channel in the raw mode.
For example, if the raw mode is "RGB", then it can contain at most 768
values, made up of red, green and blue values for the corresponding pixel
index in the 256 colors.
If the raw mode is "RGBA", then it can contain at most 1024 values,
containing red, green, blue and alpha values.
Alternatively, an 8-bit string may be used instead of an integer sequence.
:param data: A palette sequence (either a list or a string).
:param rawmode: The raw mode of the palette. Either "RGB", "RGBA", or a
mode that can be transformed to "RGB" (e.g. "R", "BGR;15", "RGBA;L").
"""
from . import ImagePalette
if self.mode not in ("L", "LA", "P", "PA"):
raise ValueError("illegal image mode")
if isinstance(data, ImagePalette.ImagePalette):
palette = ImagePalette.raw(data.rawmode, data.palette)
else:
if not isinstance(data, bytes):
data = bytes(data)
palette = ImagePalette.raw(rawmode, data)
self.mode = "PA" if "A" in self.mode else "P"
self.palette = palette
self.palette.mode = "RGB"
self.load() # install new palette
[文档] def putpixel(self, xy, value):
"""
Modifies the pixel at the given position. The color is given as
a single numerical value for single-band images, and a tuple for
multi-band images. In addition to this, RGB and RGBA tuples are
accepted for P images.
Note that this method is relatively slow. For more extensive changes,
use :py:meth:`~PIL.Image.Image.paste` or the :py:mod:`~PIL.ImageDraw`
module instead.
See:
* :py:meth:`~PIL.Image.Image.paste`
* :py:meth:`~PIL.Image.Image.putdata`
* :py:mod:`~PIL.ImageDraw`
:param xy: The pixel coordinate, given as (x, y). See
:ref:`coordinate-system`.
:param value: The pixel value.
"""
if self.readonly:
self._copy()
self.load()
if self.pyaccess:
return self.pyaccess.putpixel(xy, value)
if (
self.mode == "P"
and isinstance(value, (list, tuple))
and len(value) in [3, 4]
):
# RGB or RGBA value for a P image
value = self.palette.getcolor(value, self)
return self.im.putpixel(xy, value)
[文档] def remap_palette(self, dest_map, source_palette=None):
"""
Rewrites the image to reorder the palette.
:param dest_map: A list of indexes into the original palette.
e.g. ``[1,0]`` would swap a two item palette, and ``list(range(256))``
is the identity transform.
:param source_palette: Bytes or None.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
from . import ImagePalette
if self.mode not in ("L", "P"):
raise ValueError("illegal image mode")
if source_palette is None:
if self.mode == "P":
self.load()
source_palette = self.im.getpalette("RGB")[:768]
else: # L-mode
source_palette = bytearray(i // 3 for i in range(768))
palette_bytes = b""
new_positions = [0] * 256
# pick only the used colors from the palette
for i, oldPosition in enumerate(dest_map):
palette_bytes += source_palette[oldPosition * 3 : oldPosition * 3 + 3]
new_positions[oldPosition] = i
# replace the palette color id of all pixel with the new id
# Palette images are [0..255], mapped through a 1 or 3
# byte/color map. We need to remap the whole image
# from palette 1 to palette 2. New_positions is
# an array of indexes into palette 1. Palette 2 is
# palette 1 with any holes removed.
# We're going to leverage the convert mechanism to use the
# C code to remap the image from palette 1 to palette 2,
# by forcing the source image into 'L' mode and adding a
# mapping 'L' mode palette, then converting back to 'L'
# sans palette thus converting the image bytes, then
# assigning the optimized RGB palette.
# perf reference, 9500x4000 gif, w/~135 colors
# 14 sec prepatch, 1 sec postpatch with optimization forced.
mapping_palette = bytearray(new_positions)
m_im = self.copy()
m_im.mode = "P"
m_im.palette = ImagePalette.ImagePalette("RGB", palette=mapping_palette * 3)
# possibly set palette dirty, then
# m_im.putpalette(mapping_palette, 'L') # converts to 'P'
# or just force it.
# UNDONE -- this is part of the general issue with palettes
m_im.im.putpalette("RGB;L", m_im.palette.tobytes())
m_im = m_im.convert("L")
# Internally, we require 768 bytes for a palette.
new_palette_bytes = palette_bytes + (768 - len(palette_bytes)) * b"\x00"
m_im.putpalette(new_palette_bytes)
m_im.palette = ImagePalette.ImagePalette("RGB", palette=palette_bytes)
return m_im
def _get_safe_box(self, size, resample, box):
"""Expands the box so it includes adjacent pixels
that may be used by resampling with the given resampling filter.
"""
filter_support = _filters_support[resample] - 0.5
scale_x = (box[2] - box[0]) / size[0]
scale_y = (box[3] - box[1]) / size[1]
support_x = filter_support * scale_x
support_y = filter_support * scale_y
return (
max(0, int(box[0] - support_x)),
max(0, int(box[1] - support_y)),
min(self.size[0], math.ceil(box[2] + support_x)),
min(self.size[1], math.ceil(box[3] + support_y)),
)
[文档] def resize(self, size, resample=None, box=None, reducing_gap=None):
"""
Returns a resized copy of this image.
:param size: The requested size in pixels, as a 2-tuple:
(width, height).
:param resample: An optional resampling filter. This can be
one of :py:data:`PIL.Image.NEAREST`, :py:data:`PIL.Image.BOX`,
:py:data:`PIL.Image.BILINEAR`, :py:data:`PIL.Image.HAMMING`,
:py:data:`PIL.Image.BICUBIC` or :py:data:`PIL.Image.LANCZOS`.
If the image has mode "1" or "P", it is always set to
:py:data:`PIL.Image.NEAREST`.
If the image mode specifies a number of bits, such as "I;16", then the
default filter is :py:data:`PIL.Image.NEAREST`.
Otherwise, the default filter is :py:data:`PIL.Image.BICUBIC`.
See: :ref:`concept-filters`.
:param box: An optional 4-tuple of floats providing
the source image region to be scaled.
The values must be within (0, 0, width, height) rectangle.
If omitted or None, the entire source is used.
:param reducing_gap: Apply optimization by resizing the image
in two steps. First, reducing the image by integer times
using :py:meth:`~PIL.Image.Image.reduce`.
Second, resizing using regular resampling. The last step
changes size no less than by ``reducing_gap`` times.
``reducing_gap`` may be None (no first step is performed)
or should be greater than 1.0. The bigger ``reducing_gap``,
the closer the result to the fair resampling.
The smaller ``reducing_gap``, the faster resizing.
With ``reducing_gap`` greater or equal to 3.0, the result is
indistinguishable from fair resampling in most cases.
The default value is None (no optimization).
:returns: An :py:class:`~PIL.Image.Image` object.
"""
if resample is None:
type_special = ";" in self.mode
resample = NEAREST if type_special else BICUBIC
elif resample not in (NEAREST, BILINEAR, BICUBIC, LANCZOS, BOX, HAMMING):
message = f"Unknown resampling filter ({resample})."
filters = [
"{} ({})".format(filter[1], filter[0])
for filter in (
(NEAREST, "Image.NEAREST"),
(LANCZOS, "Image.LANCZOS"),
(BILINEAR, "Image.BILINEAR"),
(BICUBIC, "Image.BICUBIC"),
(BOX, "Image.BOX"),
(HAMMING, "Image.HAMMING"),
)
]
raise ValueError(
message + " Use " + ", ".join(filters[:-1]) + " or " + filters[-1]
)
if reducing_gap is not None and reducing_gap < 1.0:
raise ValueError("reducing_gap must be 1.0 or greater")
size = tuple(size)
if box is None:
box = (0, 0) + self.size
else:
box = tuple(box)
if self.size == size and box == (0, 0) + self.size:
return self.copy()
if self.mode in ("1", "P"):
resample = NEAREST
if self.mode in ["LA", "RGBA"] and resample != NEAREST:
im = self.convert({"LA": "La", "RGBA": "RGBa"}[self.mode])
im = im.resize(size, resample, box)
return im.convert(self.mode)
self.load()
if reducing_gap is not None and resample != NEAREST:
factor_x = int((box[2] - box[0]) / size[0] / reducing_gap) or 1
factor_y = int((box[3] - box[1]) / size[1] / reducing_gap) or 1
if factor_x > 1 or factor_y > 1:
reduce_box = self._get_safe_box(size, resample, box)
factor = (factor_x, factor_y)
if callable(self.reduce):
self = self.reduce(factor, box=reduce_box)
else:
self = Image.reduce(self, factor, box=reduce_box)
box = (
(box[0] - reduce_box[0]) / factor_x,
(box[1] - reduce_box[1]) / factor_y,
(box[2] - reduce_box[0]) / factor_x,
(box[3] - reduce_box[1]) / factor_y,
)
return self._new(self.im.resize(size, resample, box))
[文档] def reduce(self, factor, box=None):
"""
Returns a copy of the image reduced ``factor`` times.
If the size of the image is not dividable by ``factor``,
the resulting size will be rounded up.
:param factor: A greater than 0 integer or tuple of two integers
for width and height separately.
:param box: An optional 4-tuple of ints providing
the source image region to be reduced.
The values must be within ``(0, 0, width, height)`` rectangle.
If omitted or ``None``, the entire source is used.
"""
if not isinstance(factor, (list, tuple)):
factor = (factor, factor)
if box is None:
box = (0, 0) + self.size
else:
box = tuple(box)
if factor == (1, 1) and box == (0, 0) + self.size:
return self.copy()
if self.mode in ["LA", "RGBA"]:
im = self.convert({"LA": "La", "RGBA": "RGBa"}[self.mode])
im = im.reduce(factor, box)
return im.convert(self.mode)
self.load()
return self._new(self.im.reduce(factor, box))
[文档] def rotate(
self,
angle,
resample=NEAREST,
expand=0,
center=None,
translate=None,
fillcolor=None,
):
"""
Returns a rotated copy of this image. This method returns a
copy of this image, rotated the given number of degrees counter
clockwise around its centre.
:param angle: In degrees counter clockwise.
:param resample: An optional resampling filter. This can be
one of :py:data:`PIL.Image.NEAREST` (use nearest neighbour),
:py:data:`PIL.Image.BILINEAR` (linear interpolation in a 2x2
environment), or :py:data:`PIL.Image.BICUBIC`
(cubic spline interpolation in a 4x4 environment).
If omitted, or if the image has mode "1" or "P", it is
set to :py:data:`PIL.Image.NEAREST`. See :ref:`concept-filters`.
:param expand: Optional expansion flag. If true, expands the output
image to make it large enough to hold the entire rotated image.
If false or omitted, make the output image the same size as the
input image. Note that the expand flag assumes rotation around
the center and no translation.
:param center: Optional center of rotation (a 2-tuple). Origin is
the upper left corner. Default is the center of the image.
:param translate: An optional post-rotate translation (a 2-tuple).
:param fillcolor: An optional color for area outside the rotated image.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
angle = angle % 360.0
# Fast paths regardless of filter, as long as we're not
# translating or changing the center.
if not (center or translate):
if angle == 0:
return self.copy()
if angle == 180:
return self.transpose(ROTATE_180)
if angle in (90, 270) and (expand or self.width == self.height):
return self.transpose(ROTATE_90 if angle == 90 else ROTATE_270)
# Calculate the affine matrix. Note that this is the reverse
# transformation (from destination image to source) because we
# want to interpolate the (discrete) destination pixel from
# the local area around the (floating) source pixel.
# The matrix we actually want (note that it operates from the right):
# (1, 0, tx) (1, 0, cx) ( cos a, sin a, 0) (1, 0, -cx)
# (0, 1, ty) * (0, 1, cy) * (-sin a, cos a, 0) * (0, 1, -cy)
# (0, 0, 1) (0, 0, 1) ( 0, 0, 1) (0, 0, 1)
# The reverse matrix is thus:
# (1, 0, cx) ( cos -a, sin -a, 0) (1, 0, -cx) (1, 0, -tx)
# (0, 1, cy) * (-sin -a, cos -a, 0) * (0, 1, -cy) * (0, 1, -ty)
# (0, 0, 1) ( 0, 0, 1) (0, 0, 1) (0, 0, 1)
# In any case, the final translation may be updated at the end to
# compensate for the expand flag.
w, h = self.size
if translate is None:
post_trans = (0, 0)
else:
post_trans = translate
if center is None:
# FIXME These should be rounded to ints?
rotn_center = (w / 2.0, h / 2.0)
else:
rotn_center = center
angle = -math.radians(angle)
matrix = [
round(math.cos(angle), 15),
round(math.sin(angle), 15),
0.0,
round(-math.sin(angle), 15),
round(math.cos(angle), 15),
0.0,
]
def transform(x, y, matrix):
(a, b, c, d, e, f) = matrix
return a * x + b * y + c, d * x + e * y + f
matrix[2], matrix[5] = transform(
-rotn_center[0] - post_trans[0], -rotn_center[1] - post_trans[1], matrix
)
matrix[2] += rotn_center[0]
matrix[5] += rotn_center[1]
if expand:
# calculate output size
xx = []
yy = []
for x, y in ((0, 0), (w, 0), (w, h), (0, h)):
x, y = transform(x, y, matrix)
xx.append(x)
yy.append(y)
nw = math.ceil(max(xx)) - math.floor(min(xx))
nh = math.ceil(max(yy)) - math.floor(min(yy))
# We multiply a translation matrix from the right. Because of its
# special form, this is the same as taking the image of the
# translation vector as new translation vector.
matrix[2], matrix[5] = transform(-(nw - w) / 2.0, -(nh - h) / 2.0, matrix)
w, h = nw, nh
return self.transform((w, h), AFFINE, matrix, resample, fillcolor=fillcolor)
[文档] def save(self, fp, format=None, **params):
"""
Saves this image under the given filename. If no format is
specified, the format to use is determined from the filename
extension, if possible.
Keyword options can be used to provide additional instructions
to the writer. If a writer doesn't recognise an option, it is
silently ignored. The available options are described in the
:doc:`image format documentation
<../handbook/image-file-formats>` for each writer.
You can use a file object instead of a filename. In this case,
you must always specify the format. The file object must
implement the ``seek``, ``tell``, and ``write``
methods, and be opened in binary mode.
:param fp: A filename (string), pathlib.Path object or file object.
:param format: Optional format override. If omitted, the
format to use is determined from the filename extension.
If a file object was used instead of a filename, this
parameter should always be used.
:param params: Extra parameters to the image writer.
:returns: None
:exception ValueError: If the output format could not be determined
from the file name. Use the format option to solve this.
:exception OSError: If the file could not be written. The file
may have been created, and may contain partial data.
"""
filename = ""
open_fp = False
if isinstance(fp, Path):
filename = str(fp)
open_fp = True
elif isPath(fp):
filename = fp
open_fp = True
elif fp == sys.stdout:
try:
fp = sys.stdout.buffer
except AttributeError:
pass
if not filename and hasattr(fp, "name") and isPath(fp.name):
# only set the name for metadata purposes
filename = fp.name
# may mutate self!
self._ensure_mutable()
save_all = params.pop("save_all", False)
self.encoderinfo = params
self.encoderconfig = ()
preinit()
ext = os.path.splitext(filename)[1].lower()
if not format:
if ext not in EXTENSION:
init()
try:
format = EXTENSION[ext]
except KeyError as e:
raise ValueError(f"unknown file extension: {ext}") from e
if format.upper() not in SAVE:
init()
if save_all:
save_handler = SAVE_ALL[format.upper()]
else:
save_handler = SAVE[format.upper()]
if open_fp:
if params.get("append", False):
# Open also for reading ("+"), because TIFF save_all
# writer needs to go back and edit the written data.
fp = builtins.open(filename, "r+b")
else:
fp = builtins.open(filename, "w+b")
try:
save_handler(self, fp, filename)
finally:
# do what we can to clean up
if open_fp:
fp.close()
[文档] def seek(self, frame):
"""
Seeks to the given frame in this sequence file. If you seek
beyond the end of the sequence, the method raises an
``EOFError`` exception. When a sequence file is opened, the
library automatically seeks to frame 0.
See :py:meth:`~PIL.Image.Image.tell`.
If defined, :attr:`~PIL.Image.Image.n_frames` refers to the
number of available frames.
:param frame: Frame number, starting at 0.
:exception EOFError: If the call attempts to seek beyond the end
of the sequence.
"""
# overridden by file handlers
if frame != 0:
raise EOFError
[文档] def show(self, title=None, command=None):
"""
Displays this image. This method is mainly intended for debugging purposes.
This method calls :py:func:`PIL.ImageShow.show` internally. You can use
:py:func:`PIL.ImageShow.register` to override its default behaviour.
The image is first saved to a temporary file. By default, it will be in
PNG format.
On Unix, the image is then opened using the **display**, **eog** or
**xv** utility, depending on which one can be found.
On macOS, the image is opened with the native Preview application.
On Windows, the image is opened with the standard PNG display utility.
:param title: Optional title to use for the image window, where possible.
"""
if command is not None:
warnings.warn(
"The command parameter is deprecated and will be removed in Pillow 9 "
"(2022-01-02). Use a subclass of ImageShow.Viewer instead.",
DeprecationWarning,
)
_show(self, title=title, command=command)
[文档] def split(self):
"""
Split this image into individual bands. This method returns a
tuple of individual image bands from an image. For example,
splitting an "RGB" image creates three new images each
containing a copy of one of the original bands (red, green,
blue).
If you need only one band, :py:meth:`~PIL.Image.Image.getchannel`
method can be more convenient and faster.
:returns: A tuple containing bands.
"""
self.load()
if self.im.bands == 1:
ims = [self.copy()]
else:
ims = map(self._new, self.im.split())
return tuple(ims)
[文档] def getchannel(self, channel):
"""
Returns an image containing a single channel of the source image.
:param channel: What channel to return. Could be index
(0 for "R" channel of "RGB") or channel name
("A" for alpha channel of "RGBA").
:returns: An image in "L" mode.
.. versionadded:: 4.3.0
"""
self.load()
if isinstance(channel, str):
try:
channel = self.getbands().index(channel)
except ValueError as e:
raise ValueError(f'The image has no channel "{channel}"') from e
return self._new(self.im.getband(channel))
[文档] def tell(self):
"""
Returns the current frame number. See :py:meth:`~PIL.Image.Image.seek`.
If defined, :attr:`~PIL.Image.Image.n_frames` refers to the
number of available frames.
:returns: Frame number, starting with 0.
"""
return 0
[文档] def thumbnail(self, size, resample=BICUBIC, reducing_gap=2.0):
"""
Make this image into a thumbnail. This method modifies the
image to contain a thumbnail version of itself, no larger than
the given size. This method calculates an appropriate thumbnail
size to preserve the aspect of the image, calls the
:py:meth:`~PIL.Image.Image.draft` method to configure the file reader
(where applicable), and finally resizes the image.
Note that this function modifies the :py:class:`~PIL.Image.Image`
object in place. If you need to use the full resolution image as well,
apply this method to a :py:meth:`~PIL.Image.Image.copy` of the original
image.
:param size: Requested size.
:param resample: Optional resampling filter. This can be one
of :py:data:`PIL.Image.NEAREST`, :py:data:`PIL.Image.BOX`,
:py:data:`PIL.Image.BILINEAR`, :py:data:`PIL.Image.HAMMING`,
:py:data:`PIL.Image.BICUBIC` or :py:data:`PIL.Image.LANCZOS`.
If omitted, it defaults to :py:data:`PIL.Image.BICUBIC`.
(was :py:data:`PIL.Image.NEAREST` prior to version 2.5.0).
See: :ref:`concept-filters`.
:param reducing_gap: Apply optimization by resizing the image
in two steps. First, reducing the image by integer times
using :py:meth:`~PIL.Image.Image.reduce` or
:py:meth:`~PIL.Image.Image.draft` for JPEG images.
Second, resizing using regular resampling. The last step
changes size no less than by ``reducing_gap`` times.
``reducing_gap`` may be None (no first step is performed)
or should be greater than 1.0. The bigger ``reducing_gap``,
the closer the result to the fair resampling.
The smaller ``reducing_gap``, the faster resizing.
With ``reducing_gap`` greater or equal to 3.0, the result is
indistinguishable from fair resampling in most cases.
The default value is 2.0 (very close to fair resampling
while still being faster in many cases).
:returns: None
"""
x, y = map(math.floor, size)
if x >= self.width and y >= self.height:
return
def round_aspect(number, key):
return max(min(math.floor(number), math.ceil(number), key=key), 1)
# preserve aspect ratio
aspect = self.width / self.height
if x / y >= aspect:
x = round_aspect(y * aspect, key=lambda n: abs(aspect - n / y))
else:
y = round_aspect(
x / aspect, key=lambda n: 0 if n == 0 else abs(aspect - x / n)
)
size = (x, y)
box = None
if reducing_gap is not None:
res = self.draft(None, (size[0] * reducing_gap, size[1] * reducing_gap))
if res is not None:
box = res[1]
if self.size != size:
im = self.resize(size, resample, box=box, reducing_gap=reducing_gap)
self.im = im.im
self._size = size
self.mode = self.im.mode
self.readonly = 0
self.pyaccess = None
# FIXME: the different transform methods need further explanation
# instead of bloating the method docs, add a separate chapter.
[文档] def transform(
self, size, method, data=None, resample=NEAREST, fill=1, fillcolor=None
):
"""
Transforms this image. This method creates a new image with the
given size, and the same mode as the original, and copies data
to the new image using the given transform.
:param size: The output size.
:param method: The transformation method. This is one of
:py:data:`PIL.Image.EXTENT` (cut out a rectangular subregion),
:py:data:`PIL.Image.AFFINE` (affine transform),
:py:data:`PIL.Image.PERSPECTIVE` (perspective transform),
:py:data:`PIL.Image.QUAD` (map a quadrilateral to a rectangle), or
:py:data:`PIL.Image.MESH` (map a number of source quadrilaterals
in one operation).
It may also be an :py:class:`~PIL.Image.ImageTransformHandler`
object::
class Example(Image.ImageTransformHandler):
def transform(self, size, data, resample, fill=1):
# Return result
It may also be an object with a ``method.getdata`` method
that returns a tuple supplying new ``method`` and ``data`` values::
class Example:
def getdata(self):
method = Image.EXTENT
data = (0, 0, 100, 100)
return method, data
:param data: Extra data to the transformation method.
:param resample: Optional resampling filter. It can be one of
:py:data:`PIL.Image.NEAREST` (use nearest neighbour),
:py:data:`PIL.Image.BILINEAR` (linear interpolation in a 2x2
environment), or :py:data:`PIL.Image.BICUBIC` (cubic spline
interpolation in a 4x4 environment). If omitted, or if the image
has mode "1" or "P", it is set to :py:data:`PIL.Image.NEAREST`.
See: :ref:`concept-filters`.
:param fill: If ``method`` is an
:py:class:`~PIL.Image.ImageTransformHandler` object, this is one of
the arguments passed to it. Otherwise, it is unused.
:param fillcolor: Optional fill color for the area outside the
transform in the output image.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
if self.mode in ("LA", "RGBA") and resample != NEAREST:
return (
self.convert({"LA": "La", "RGBA": "RGBa"}[self.mode])
.transform(size, method, data, resample, fill, fillcolor)
.convert(self.mode)
)
if isinstance(method, ImageTransformHandler):
return method.transform(size, self, resample=resample, fill=fill)
if hasattr(method, "getdata"):
# compatibility w. old-style transform objects
method, data = method.getdata()
if data is None:
raise ValueError("missing method data")
im = new(self.mode, size, fillcolor)
if self.mode == "P" and self.palette:
im.palette = self.palette.copy()
im.info = self.info.copy()
if method == MESH:
# list of quads
for box, quad in data:
im.__transformer(box, self, QUAD, quad, resample, fillcolor is None)
else:
im.__transformer(
(0, 0) + size, self, method, data, resample, fillcolor is None
)
return im
def __transformer(self, box, image, method, data, resample=NEAREST, fill=1):
w = box[2] - box[0]
h = box[3] - box[1]
if method == AFFINE:
data = data[0:6]
elif method == EXTENT:
# convert extent to an affine transform
x0, y0, x1, y1 = data
xs = (x1 - x0) / w
ys = (y1 - y0) / h
method = AFFINE
data = (xs, 0, x0, 0, ys, y0)
elif method == PERSPECTIVE:
data = data[0:8]
elif method == QUAD:
# quadrilateral warp. data specifies the four corners
# given as NW, SW, SE, and NE.
nw = data[0:2]
sw = data[2:4]
se = data[4:6]
ne = data[6:8]
x0, y0 = nw
As = 1.0 / w
At = 1.0 / h
data = (
x0,
(ne[0] - x0) * As,
(sw[0] - x0) * At,
(se[0] - sw[0] - ne[0] + x0) * As * At,
y0,
(ne[1] - y0) * As,
(sw[1] - y0) * At,
(se[1] - sw[1] - ne[1] + y0) * As * At,
)
else:
raise ValueError("unknown transformation method")
if resample not in (NEAREST, BILINEAR, BICUBIC):
if resample in (BOX, HAMMING, LANCZOS):
message = {
BOX: "Image.BOX",
HAMMING: "Image.HAMMING",
LANCZOS: "Image.LANCZOS/Image.ANTIALIAS",
}[resample] + f" ({resample}) cannot be used."
else:
message = f"Unknown resampling filter ({resample})."
filters = [
"{} ({})".format(filter[1], filter[0])
for filter in (
(NEAREST, "Image.NEAREST"),
(BILINEAR, "Image.BILINEAR"),
(BICUBIC, "Image.BICUBIC"),
)
]
raise ValueError(
message + " Use " + ", ".join(filters[:-1]) + " or " + filters[-1]
)
image.load()
self.load()
if image.mode in ("1", "P"):
resample = NEAREST
self.im.transform2(box, image.im, method, data, resample, fill)
[文档] def transpose(self, method):
"""
Transpose image (flip or rotate in 90 degree steps)
:param method: One of :py:data:`PIL.Image.FLIP_LEFT_RIGHT`,
:py:data:`PIL.Image.FLIP_TOP_BOTTOM`, :py:data:`PIL.Image.ROTATE_90`,
:py:data:`PIL.Image.ROTATE_180`, :py:data:`PIL.Image.ROTATE_270`,
:py:data:`PIL.Image.TRANSPOSE` or :py:data:`PIL.Image.TRANSVERSE`.
:returns: Returns a flipped or rotated copy of this image.
"""
self.load()
return self._new(self.im.transpose(method))
[文档] def effect_spread(self, distance):
"""
Randomly spread pixels in an image.
:param distance: Distance to spread pixels.
"""
self.load()
return self._new(self.im.effect_spread(distance))
def toqimage(self):
"""Returns a QImage copy of this image"""
from . import ImageQt
if not ImageQt.qt_is_installed:
raise ImportError("Qt bindings are not installed")
return ImageQt.toqimage(self)
def toqpixmap(self):
"""Returns a QPixmap copy of this image"""
from . import ImageQt
if not ImageQt.qt_is_installed:
raise ImportError("Qt bindings are not installed")
return ImageQt.toqpixmap(self)
# --------------------------------------------------------------------
# Abstract handlers.
[文档]class ImagePointHandler:
"""
Used as a mixin by point transforms
(for use with :py:meth:`~PIL.Image.Image.point`)
"""
pass
[文档]class ImageTransformHandler:
"""
Used as a mixin by geometry transforms
(for use with :py:meth:`~PIL.Image.Image.transform`)
"""
pass
# --------------------------------------------------------------------
# Factories
#
# Debugging
def _wedge():
"""Create greyscale wedge (for debugging only)"""
return Image()._new(core.wedge("L"))
def _check_size(size):
"""
Common check to enforce type and sanity check on size tuples
:param size: Should be a 2 tuple of (width, height)
:returns: True, or raises a ValueError
"""
if not isinstance(size, (list, tuple)):
raise ValueError("Size must be a tuple")
if len(size) != 2:
raise ValueError("Size must be a tuple of length 2")
if size[0] < 0 or size[1] < 0:
raise ValueError("Width and height must be >= 0")
return True
[文档]def new(mode, size, color=0):
"""
Creates a new image with the given mode and size.
:param mode: The mode to use for the new image. See:
:ref:`concept-modes`.
:param size: A 2-tuple, containing (width, height) in pixels.
:param color: What color to use for the image. Default is black.
If given, this should be a single integer or floating point value
for single-band modes, and a tuple for multi-band modes (one value
per band). When creating RGB images, you can also use color
strings as supported by the ImageColor module. If the color is
None, the image is not initialised.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
_check_size(size)
if color is None:
# don't initialize
return Image()._new(core.new(mode, size))
if isinstance(color, str):
# css3-style specifier
from . import ImageColor
color = ImageColor.getcolor(color, mode)
im = Image()
if mode == "P" and isinstance(color, (list, tuple)) and len(color) in [3, 4]:
# RGB or RGBA value for a P image
from . import ImagePalette
im.palette = ImagePalette.ImagePalette()
color = im.palette.getcolor(color)
return im._new(core.fill(mode, size, color))
[文档]def frombytes(mode, size, data, decoder_name="raw", *args):
"""
Creates a copy of an image memory from pixel data in a buffer.
In its simplest form, this function takes three arguments
(mode, size, and unpacked pixel data).
You can also use any pixel decoder supported by PIL. For more
information on available decoders, see the section
:ref:`Writing Your Own File Decoder <file-decoders>`.
Note that this function decodes pixel data only, not entire images.
If you have an entire image in a string, wrap it in a
:py:class:`~io.BytesIO` object, and use :py:func:`~PIL.Image.open` to load
it.
:param mode: The image mode. See: :ref:`concept-modes`.
:param size: The image size.
:param data: A byte buffer containing raw data for the given mode.
:param decoder_name: What decoder to use.
:param args: Additional parameters for the given decoder.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
_check_size(size)
# may pass tuple instead of argument list
if len(args) == 1 and isinstance(args[0], tuple):
args = args[0]
if decoder_name == "raw" and args == ():
args = mode
im = new(mode, size)
im.frombytes(data, decoder_name, args)
return im
[文档]def frombuffer(mode, size, data, decoder_name="raw", *args):
"""
Creates an image memory referencing pixel data in a byte buffer.
This function is similar to :py:func:`~PIL.Image.frombytes`, but uses data
in the byte buffer, where possible. This means that changes to the
original buffer object are reflected in this image). Not all modes can
share memory; supported modes include "L", "RGBX", "RGBA", and "CMYK".
Note that this function decodes pixel data only, not entire images.
If you have an entire image file in a string, wrap it in a
:py:class:`~io.BytesIO` object, and use :py:func:`~PIL.Image.open` to load it.
In the current version, the default parameters used for the "raw" decoder
differs from that used for :py:func:`~PIL.Image.frombytes`. This is a
bug, and will probably be fixed in a future release. The current release
issues a warning if you do this; to disable the warning, you should provide
the full set of parameters. See below for details.
:param mode: The image mode. See: :ref:`concept-modes`.
:param size: The image size.
:param data: A bytes or other buffer object containing raw
data for the given mode.
:param decoder_name: What decoder to use.
:param args: Additional parameters for the given decoder. For the
default encoder ("raw"), it's recommended that you provide the
full set of parameters::
frombuffer(mode, size, data, "raw", mode, 0, 1)
:returns: An :py:class:`~PIL.Image.Image` object.
.. versionadded:: 1.1.4
"""
_check_size(size)
# may pass tuple instead of argument list
if len(args) == 1 and isinstance(args[0], tuple):
args = args[0]
if decoder_name == "raw":
if args == ():
args = mode, 0, 1
if args[0] in _MAPMODES:
im = new(mode, (1, 1))
im = im._new(core.map_buffer(data, size, decoder_name, 0, args))
im.readonly = 1
return im
return frombytes(mode, size, data, decoder_name, args)
[文档]def fromarray(obj, mode=None):
"""
Creates an image memory from an object exporting the array interface
(using the buffer protocol).
If ``obj`` is not contiguous, then the ``tobytes`` method is called
and :py:func:`~PIL.Image.frombuffer` is used.
If you have an image in NumPy::
from PIL import Image
import numpy as np
im = Image.open('hopper.jpg')
a = np.asarray(im)
Then this can be used to convert it to a Pillow image::
im = Image.fromarray(a)
:param obj: Object with array interface
:param mode: Mode to use (will be determined from type if None)
See: :ref:`concept-modes`.
:returns: An image object.
.. versionadded:: 1.1.6
"""
arr = obj.__array_interface__
shape = arr["shape"]
ndim = len(shape)
strides = arr.get("strides", None)
if mode is None:
try:
typekey = (1, 1) + shape[2:], arr["typestr"]
except KeyError as e:
raise TypeError("Cannot handle this data type") from e
try:
mode, rawmode = _fromarray_typemap[typekey]
except KeyError as e:
raise TypeError("Cannot handle this data type: %s, %s" % typekey) from e
else:
rawmode = mode
if mode in ["1", "L", "I", "P", "F"]:
ndmax = 2
elif mode == "RGB":
ndmax = 3
else:
ndmax = 4
if ndim > ndmax:
raise ValueError(f"Too many dimensions: {ndim} > {ndmax}.")
size = 1 if ndim == 1 else shape[1], shape[0]
if strides is not None:
if hasattr(obj, "tobytes"):
obj = obj.tobytes()
else:
obj = obj.tostring()
return frombuffer(mode, size, obj, "raw", rawmode, 0, 1)
def fromqimage(im):
"""Creates an image instance from a QImage image"""
from . import ImageQt
if not ImageQt.qt_is_installed:
raise ImportError("Qt bindings are not installed")
return ImageQt.fromqimage(im)
def fromqpixmap(im):
"""Creates an image instance from a QPixmap image"""
from . import ImageQt
if not ImageQt.qt_is_installed:
raise ImportError("Qt bindings are not installed")
return ImageQt.fromqpixmap(im)
_fromarray_typemap = {
# (shape, typestr) => mode, rawmode
# first two members of shape are set to one
((1, 1), "|b1"): ("1", "1;8"),
((1, 1), "|u1"): ("L", "L"),
((1, 1), "|i1"): ("I", "I;8"),
((1, 1), "<u2"): ("I", "I;16"),
((1, 1), ">u2"): ("I", "I;16B"),
((1, 1), "<i2"): ("I", "I;16S"),
((1, 1), ">i2"): ("I", "I;16BS"),
((1, 1), "<u4"): ("I", "I;32"),
((1, 1), ">u4"): ("I", "I;32B"),
((1, 1), "<i4"): ("I", "I;32S"),
((1, 1), ">i4"): ("I", "I;32BS"),
((1, 1), "<f4"): ("F", "F;32F"),
((1, 1), ">f4"): ("F", "F;32BF"),
((1, 1), "<f8"): ("F", "F;64F"),
((1, 1), ">f8"): ("F", "F;64BF"),
((1, 1, 2), "|u1"): ("LA", "LA"),
((1, 1, 3), "|u1"): ("RGB", "RGB"),
((1, 1, 4), "|u1"): ("RGBA", "RGBA"),
}
# shortcuts
_fromarray_typemap[((1, 1), _ENDIAN + "i4")] = ("I", "I")
_fromarray_typemap[((1, 1), _ENDIAN + "f4")] = ("F", "F")
def _decompression_bomb_check(size):
if MAX_IMAGE_PIXELS is None:
return
pixels = size[0] * size[1]
if pixels > 2 * MAX_IMAGE_PIXELS:
raise DecompressionBombError(
f"Image size ({pixels} pixels) exceeds limit of {2 * MAX_IMAGE_PIXELS} "
"pixels, could be decompression bomb DOS attack."
)
if pixels > MAX_IMAGE_PIXELS:
warnings.warn(
f"Image size ({pixels} pixels) exceeds limit of {MAX_IMAGE_PIXELS} pixels, "
"could be decompression bomb DOS attack.",
DecompressionBombWarning,
)
[文档]def open(fp, mode="r", formats=None):
"""
Opens and identifies the given image file.
This is a lazy operation; this function identifies the file, but
the file remains open and the actual image data is not read from
the file until you try to process the data (or call the
:py:meth:`~PIL.Image.Image.load` method). See
:py:func:`~PIL.Image.new`. See :ref:`file-handling`.
:param fp: A filename (string), pathlib.Path object or a file object.
The file object must implement ``file.read``,
``file.seek``, and ``file.tell`` methods,
and be opened in binary mode.
:param mode: The mode. If given, this argument must be "r".
:param formats: A list or tuple of formats to attempt to load the file in.
This can be used to restrict the set of formats checked.
Pass ``None`` to try all supported formats. You can print the set of
available formats by running ``python3 -m PIL`` or using
the :py:func:`PIL.features.pilinfo` function.
:returns: An :py:class:`~PIL.Image.Image` object.
:exception FileNotFoundError: If the file cannot be found.
:exception PIL.UnidentifiedImageError: If the image cannot be opened and
identified.
:exception ValueError: If the ``mode`` is not "r", or if a ``StringIO``
instance is used for ``fp``.
:exception TypeError: If ``formats`` is not ``None``, a list or a tuple.
"""
if mode != "r":
raise ValueError(f"bad mode {repr(mode)}")
elif isinstance(fp, io.StringIO):
raise ValueError(
"StringIO cannot be used to open an image. "
"Binary data must be used instead."
)
if formats is None:
formats = ID
elif not isinstance(formats, (list, tuple)):
raise TypeError("formats must be a list or tuple")
exclusive_fp = False
filename = ""
if isinstance(fp, Path):
filename = str(fp.resolve())
elif isPath(fp):
filename = fp
if filename:
fp = builtins.open(filename, "rb")
exclusive_fp = True
try:
fp.seek(0)
except (AttributeError, io.UnsupportedOperation):
fp = io.BytesIO(fp.read())
exclusive_fp = True
prefix = fp.read(16)
preinit()
accept_warnings = []
def _open_core(fp, filename, prefix, formats):
for i in formats:
i = i.upper()
if i not in OPEN:
init()
try:
factory, accept = OPEN[i]
result = not accept or accept(prefix)
if type(result) in [str, bytes]:
accept_warnings.append(result)
elif result:
fp.seek(0)
im = factory(fp, filename)
_decompression_bomb_check(im.size)
return im
except (SyntaxError, IndexError, TypeError, struct.error):
# Leave disabled by default, spams the logs with image
# opening failures that are entirely expected.
# logger.debug("", exc_info=True)
continue
except BaseException:
if exclusive_fp:
fp.close()
raise
return None
im = _open_core(fp, filename, prefix, formats)
if im is None:
if init():
im = _open_core(fp, filename, prefix, formats)
if im:
im._exclusive_fp = exclusive_fp
return im
if exclusive_fp:
fp.close()
for message in accept_warnings:
warnings.warn(message)
raise UnidentifiedImageError(
"cannot identify image file %r" % (filename if filename else fp)
)
#
# Image processing.
[文档]def alpha_composite(im1, im2):
"""
Alpha composite im2 over im1.
:param im1: The first image. Must have mode RGBA.
:param im2: The second image. Must have mode RGBA, and the same size as
the first image.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
im1.load()
im2.load()
return im1._new(core.alpha_composite(im1.im, im2.im))
[文档]def blend(im1, im2, alpha):
"""
Creates a new image by interpolating between two input images, using
a constant alpha.::
out = image1 * (1.0 - alpha) + image2 * alpha
:param im1: The first image.
:param im2: The second image. Must have the same mode and size as
the first image.
:param alpha: The interpolation alpha factor. If alpha is 0.0, a
copy of the first image is returned. If alpha is 1.0, a copy of
the second image is returned. There are no restrictions on the
alpha value. If necessary, the result is clipped to fit into
the allowed output range.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
im1.load()
im2.load()
return im1._new(core.blend(im1.im, im2.im, alpha))
[文档]def composite(image1, image2, mask):
"""
Create composite image by blending images using a transparency mask.
:param image1: The first image.
:param image2: The second image. Must have the same mode and
size as the first image.
:param mask: A mask image. This image can have mode
"1", "L", or "RGBA", and must have the same size as the
other two images.
"""
image = image2.copy()
image.paste(image1, None, mask)
return image
[文档]def eval(image, *args):
"""
Applies the function (which should take one argument) to each pixel
in the given image. If the image has more than one band, the same
function is applied to each band. Note that the function is
evaluated once for each possible pixel value, so you cannot use
random components or other generators.
:param image: The input image.
:param function: A function object, taking one integer argument.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
return image.point(args[0])
[文档]def merge(mode, bands):
"""
Merge a set of single band images into a new multiband image.
:param mode: The mode to use for the output image. See:
:ref:`concept-modes`.
:param bands: A sequence containing one single-band image for
each band in the output image. All bands must have the
same size.
:returns: An :py:class:`~PIL.Image.Image` object.
"""
if getmodebands(mode) != len(bands) or "*" in mode:
raise ValueError("wrong number of bands")
for band in bands[1:]:
if band.mode != getmodetype(mode):
raise ValueError("mode mismatch")
if band.size != bands[0].size:
raise ValueError("size mismatch")
for band in bands:
band.load()
return bands[0]._new(core.merge(mode, *[b.im for b in bands]))
# --------------------------------------------------------------------
# Plugin registry
[文档]def register_open(id, factory, accept=None):
"""
Register an image file plugin. This function should not be used
in application code.
:param id: An image format identifier.
:param factory: An image file factory method.
:param accept: An optional function that can be used to quickly
reject images having another format.
"""
id = id.upper()
ID.append(id)
OPEN[id] = factory, accept
[文档]def register_mime(id, mimetype):
"""
Registers an image MIME type. This function should not be used
in application code.
:param id: An image format identifier.
:param mimetype: The image MIME type for this format.
"""
MIME[id.upper()] = mimetype
[文档]def register_save(id, driver):
"""
Registers an image save function. This function should not be
used in application code.
:param id: An image format identifier.
:param driver: A function to save images in this format.
"""
SAVE[id.upper()] = driver
[文档]def register_save_all(id, driver):
"""
Registers an image function to save all the frames
of a multiframe format. This function should not be
used in application code.
:param id: An image format identifier.
:param driver: A function to save images in this format.
"""
SAVE_ALL[id.upper()] = driver
[文档]def register_extension(id, extension):
"""
Registers an image extension. This function should not be
used in application code.
:param id: An image format identifier.
:param extension: An extension used for this format.
"""
EXTENSION[extension.lower()] = id.upper()
[文档]def register_extensions(id, extensions):
"""
Registers image extensions. This function should not be
used in application code.
:param id: An image format identifier.
:param extensions: A list of extensions used for this format.
"""
for extension in extensions:
register_extension(id, extension)
[文档]def registered_extensions():
"""
Returns a dictionary containing all file extensions belonging
to registered plugins
"""
if not EXTENSION:
init()
return EXTENSION
[文档]def register_decoder(name, decoder):
"""
Registers an image decoder. This function should not be
used in application code.
:param name: The name of the decoder
:param decoder: A callable(mode, args) that returns an
ImageFile.PyDecoder object
.. versionadded:: 4.1.0
"""
DECODERS[name] = decoder
[文档]def register_encoder(name, encoder):
"""
Registers an image encoder. This function should not be
used in application code.
:param name: The name of the encoder
:param encoder: A callable(mode, args) that returns an
ImageFile.PyEncoder object
.. versionadded:: 4.1.0
"""
ENCODERS[name] = encoder
# --------------------------------------------------------------------
# Simple display support.
def _show(image, **options):
options["_internal_pillow"] = True
_showxv(image, **options)
def _showxv(image, title=None, **options):
from . import ImageShow
if "_internal_pillow" in options:
del options["_internal_pillow"]
else:
warnings.warn(
"_showxv is deprecated and will be removed in Pillow 9 (2022-01-02). "
"Use Image.show instead.",
DeprecationWarning,
)
ImageShow.show(image, title, **options)
# --------------------------------------------------------------------
# Effects
[文档]def effect_mandelbrot(size, extent, quality):
"""
Generate a Mandelbrot set covering the given extent.
:param size: The requested size in pixels, as a 2-tuple:
(width, height).
:param extent: The extent to cover, as a 4-tuple:
(x0, y0, x1, y2).
:param quality: Quality.
"""
return Image()._new(core.effect_mandelbrot(size, extent, quality))
[文档]def effect_noise(size, sigma):
"""
Generate Gaussian noise centered around 128.
:param size: The requested size in pixels, as a 2-tuple:
(width, height).
:param sigma: Standard deviation of noise.
"""
return Image()._new(core.effect_noise(size, sigma))
[文档]def linear_gradient(mode):
"""
Generate 256x256 linear gradient from black to white, top to bottom.
:param mode: Input mode.
"""
return Image()._new(core.linear_gradient(mode))
[文档]def radial_gradient(mode):
"""
Generate 256x256 radial gradient from black to white, centre to edge.
:param mode: Input mode.
"""
return Image()._new(core.radial_gradient(mode))
# --------------------------------------------------------------------
# Resources
def _apply_env_variables(env=None):
if env is None:
env = os.environ
for var_name, setter in [
("PILLOW_ALIGNMENT", core.set_alignment),
("PILLOW_BLOCK_SIZE", core.set_block_size),
("PILLOW_BLOCKS_MAX", core.set_blocks_max),
]:
if var_name not in env:
continue
var = env[var_name].lower()
units = 1
for postfix, mul in [("k", 1024), ("m", 1024 * 1024)]:
if var.endswith(postfix):
units = mul
var = var[: -len(postfix)]
try:
var = int(var) * units
except ValueError:
warnings.warn(f"{var_name} is not int")
continue
try:
setter(var)
except ValueError as e:
warnings.warn(f"{var_name}: {e}")
_apply_env_variables()
atexit.register(core.clear_cache)
[文档]class Exif(MutableMapping):
endian = None
def __init__(self):
self._data = {}
self._ifds = {}
self._info = None
self._loaded_exif = None
def _fixup(self, value):
try:
if len(value) == 1 and isinstance(value, tuple):
return value[0]
except Exception:
pass
return value
def _fixup_dict(self, src_dict):
# Helper function
# returns a dict with any single item tuples/lists as individual values
return {k: self._fixup(v) for k, v in src_dict.items()}
def _get_ifd_dict(self, offset):
try:
# an offset pointer to the location of the nested embedded IFD.
# It should be a long, but may be corrupted.
self.fp.seek(offset)
except (KeyError, TypeError):
pass
else:
from . import TiffImagePlugin
info = TiffImagePlugin.ImageFileDirectory_v2(self.head)
info.load(self.fp)
return self._fixup_dict(info)
def _get_head(self):
if self.endian == "<":
return b"II\x2A\x00\x08\x00\x00\x00"
else:
return b"MM\x00\x2A\x00\x00\x00\x08"
[文档] def load(self, data):
# Extract EXIF information. This is highly experimental,
# and is likely to be replaced with something better in a future
# version.
# The EXIF record consists of a TIFF file embedded in a JPEG
# application marker (!).
if data == self._loaded_exif:
return
self._loaded_exif = data
self._data.clear()
self._ifds.clear()
if not data:
self._info = None
return
if data.startswith(b"Exif\x00\x00"):
data = data[6:]
self.fp = io.BytesIO(data)
self.head = self.fp.read(8)
# process dictionary
from . import TiffImagePlugin
self._info = TiffImagePlugin.ImageFileDirectory_v2(self.head)
self.endian = self._info._endian
self.fp.seek(self._info.next)
self._info.load(self.fp)
[文档] def load_from_fp(self, fp, offset=None):
self._loaded_exif = None
self._data.clear()
self._ifds.clear()
# process dictionary
from . import TiffImagePlugin
self.fp = fp
if offset is not None:
self.head = self._get_head()
else:
self.head = self.fp.read(8)
self._info = TiffImagePlugin.ImageFileDirectory_v2(self.head)
if self.endian is None:
self.endian = self._info._endian
if offset is None:
offset = self._info.next
self.fp.seek(offset)
self._info.load(self.fp)
def _get_merged_dict(self):
merged_dict = dict(self)
# get EXIF extension
if 0x8769 in self:
ifd = self._get_ifd_dict(self[0x8769])
if ifd:
merged_dict.update(ifd)
# GPS
if 0x8825 in self:
merged_dict[0x8825] = self._get_ifd_dict(self[0x8825])
return merged_dict
[文档] def tobytes(self, offset=8):
from . import TiffImagePlugin
head = self._get_head()
ifd = TiffImagePlugin.ImageFileDirectory_v2(ifh=head)
for tag, value in self.items():
if tag in [0x8769, 0x8225, 0x8825] and not isinstance(value, dict):
value = self.get_ifd(tag)
if (
tag == 0x8769
and 0xA005 in value
and not isinstance(value[0xA005], dict)
):
value = value.copy()
value[0xA005] = self.get_ifd(0xA005)
ifd[tag] = value
return b"Exif\x00\x00" + head + ifd.tobytes(offset)
[文档] def get_ifd(self, tag):
if tag not in self._ifds:
if tag in [0x8769, 0x8825]:
# exif, gpsinfo
if tag in self:
self._ifds[tag] = self._get_ifd_dict(self[tag])
elif tag in [0xA005, 0x927C]:
# interop, makernote
if 0x8769 not in self._ifds:
self.get_ifd(0x8769)
tag_data = self._ifds[0x8769][tag]
if tag == 0x927C:
# makernote
from .TiffImagePlugin import ImageFileDirectory_v2
if tag_data[:8] == b"FUJIFILM":
ifd_offset = i32le(tag_data, 8)
ifd_data = tag_data[ifd_offset:]
makernote = {}
for i in range(0, struct.unpack("<H", ifd_data[:2])[0]):
ifd_tag, typ, count, data = struct.unpack(
"<HHL4s", ifd_data[i * 12 + 2 : (i + 1) * 12 + 2]
)
try:
(
unit_size,
handler,
) = ImageFileDirectory_v2._load_dispatch[typ]
except KeyError:
continue
size = count * unit_size
if size > 4:
(offset,) = struct.unpack("<L", data)
data = ifd_data[offset - 12 : offset + size - 12]
else:
data = data[:size]
if len(data) != size:
warnings.warn(
"Possibly corrupt EXIF MakerNote data. "
f"Expecting to read {size} bytes but only got "
f"{len(data)}. Skipping tag {ifd_tag}"
)
continue
if not data:
continue
makernote[ifd_tag] = handler(
ImageFileDirectory_v2(), data, False
)
self._ifds[tag] = dict(self._fixup_dict(makernote))
elif self.get(0x010F) == "Nintendo":
makernote = {}
for i in range(0, struct.unpack(">H", tag_data[:2])[0]):
ifd_tag, typ, count, data = struct.unpack(
">HHL4s", tag_data[i * 12 + 2 : (i + 1) * 12 + 2]
)
if ifd_tag == 0x1101:
# CameraInfo
(offset,) = struct.unpack(">L", data)
self.fp.seek(offset)
camerainfo = {"ModelID": self.fp.read(4)}
self.fp.read(4)
# Seconds since 2000
camerainfo["TimeStamp"] = i32le(self.fp.read(12))
self.fp.read(4)
camerainfo["InternalSerialNumber"] = self.fp.read(4)
self.fp.read(12)
parallax = self.fp.read(4)
handler = ImageFileDirectory_v2._load_dispatch[
TiffTags.FLOAT
][1]
camerainfo["Parallax"] = handler(
ImageFileDirectory_v2(), parallax, False
)
self.fp.read(4)
camerainfo["Category"] = self.fp.read(2)
makernote = {0x1101: dict(self._fixup_dict(camerainfo))}
self._ifds[tag] = makernote
else:
# interop
self._ifds[tag] = self._get_ifd_dict(tag_data)
return self._ifds.get(tag, {})
def __str__(self):
if self._info is not None:
# Load all keys into self._data
for tag in self._info.keys():
self[tag]
return str(self._data)
def __len__(self):
keys = set(self._data)
if self._info is not None:
keys.update(self._info)
return len(keys)
def __getitem__(self, tag):
if self._info is not None and tag not in self._data and tag in self._info:
self._data[tag] = self._fixup(self._info[tag])
del self._info[tag]
return self._data[tag]
def __contains__(self, tag):
return tag in self._data or (self._info is not None and tag in self._info)
def __setitem__(self, tag, value):
if self._info is not None and tag in self._info:
del self._info[tag]
self._data[tag] = value
def __delitem__(self, tag):
if self._info is not None and tag in self._info:
del self._info[tag]
else:
del self._data[tag]
def __iter__(self):
keys = set(self._data)
if self._info is not None:
keys.update(self._info)
return iter(keys)
讨论区