python-pillow/Pillow
1
1
Fork 0
mirror of https://github.com/python-pillow/Pillow.git synced 2024-09-21 11:28:58 +03:00
Code Issues Packages Projects Releases Wiki Activity
fc035814bd
Pillow/PIL/Image.py
Brian Crowell fc035814bd py3k: map and filter to list comprehensions 
What's really going on is that map() and filter() return iterators in py3k.
I've just gone ahead and turned them all into list comprehensions, because
I find them much easier to read.
2013-01-10 08:46:43 -06:00

2142 lines
66 KiB
Python
Raw Blame History

#
# 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.
#
VERSION = "1.1.7"
try:
import warnings
except ImportError:
warnings = None
class _imaging_not_installed:
# module placeholder
def __getattr__(self, id):
raise ImportError("The _imaging C module is not installed")
try:
# give Tk a chance to set up the environment, in case we're
# using an _imaging module linked against libtcl/libtk (use
# __import__ to hide this from naive packagers; we don't really
# depend on Tk unless ImageTk is used, and that module already
# imports Tkinter)
__import__("FixTk")
except ImportError:
pass
try:
# If the _imaging C module is not present, you can still use
# the "open" function to identify files, but you cannot load
# them. Note that other modules should not refer to _imaging
# directly; import Image and use the Image.core variable instead.
import _imaging as core
except ImportError as v:
core = _imaging_not_installed()
if str(v)[:20] == "Module use of python" and warnings:
# 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; most PIL functions will be disabled",
RuntimeWarning
)
import ImageMode
import ImagePalette
import os, sys
# type stuff
from types import IntType, StringType, TupleType
import collections
try:
UnicodeStringType = type(unicode(""))
##
# (Internal) Checks if an object is a string. If the current
# Python version supports Unicode, this checks for both 8-bit
# and Unicode strings.
def isStringType(t):
return isinstance(t, StringType) or isinstance(t, UnicodeStringType)
except NameError:
def isStringType(t):
return isinstance(t, StringType)
##
# (Internal) Checks if an object is a tuple.
def isTupleType(t):
return isinstance(t, TupleType)
##
# (Internal) Checks if an object is an image object.
def isImageType(t):
return hasattr(t, "im")
##
# (Internal) Checks if an object is a string, and that it points to a
# directory.
def isDirectory(f):
return isStringType(f) and os.path.isdir(f)
from operator import isNumberType, isSequenceType
#
# Debug level
DEBUG = 0
#
# Constants (also defined in _imagingmodule.c!)
NONE = 0
# transpose
FLIP_LEFT_RIGHT = 0
FLIP_TOP_BOTTOM = 1
ROTATE_90 = 2
ROTATE_180 = 3
ROTATE_270 = 4
# transforms
AFFINE = 0
EXTENT = 1
PERSPECTIVE = 2
QUAD = 3
MESH = 4
# resampling filters
NONE = 0
NEAREST = 0
ANTIALIAS = 1 # 3-lobed lanczos
LINEAR = BILINEAR = 2
CUBIC = BICUBIC = 3
# dithers
NONE = 0
NEAREST = 0
ORDERED = 1 # Not yet implemented
RASTERIZE = 2 # Not yet implemented
FLOYDSTEINBERG = 3 # default
# palettes/quantizers
WEB = 0
ADAPTIVE = 1
# categories
NORMAL = 0
SEQUENCE = 1
CONTAINER = 2
# --------------------------------------------------------------------
# Registries
ID = []
OPEN = {}
MIME = {}
SAVE = {}
EXTENSION = {}
# --------------------------------------------------------------------
# Modes supported by this version
_MODEINFO = {
# NOTE: this table will be removed in future versions. use
# getmode* functions or ImageMode descriptors instead.
# official modes
"1": ("L", "L", ("1",)),
"L": ("L", "L", ("L",)),
"I": ("L", "I", ("I",)),
"F": ("L", "F", ("F",)),
"P": ("RGB", "L", ("P",)),
"RGB": ("RGB", "L", ("R", "G", "B")),
"RGBX": ("RGB", "L", ("R", "G", "B", "X")),
"RGBA": ("RGB", "L", ("R", "G", "B", "A")),
"CMYK": ("RGB", "L", ("C", "M", "Y", "K")),
"YCbCr": ("RGB", "L", ("Y", "Cb", "Cr")),
# Experimental modes include I;16, I;16L, I;16B, RGBa, BGR;15, and
# BGR;24. Use these modes only if you know exactly what you're
# doing...
}
try:
byteorder = sys.byteorder
except AttributeError:
import struct
if struct.unpack("h", "\0\1")[0] == 1:
byteorder = "big"
else:
byteorder = "little"
if byteorder == 'little':
_ENDIAN = '<'
else:
_ENDIAN = '>'
_MODE_CONV = {
# official modes
"1": ('|b1', None), # broken
"L": ('|u1', None),
"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', 4),
}
def _conv_type_shape(im):
shape = im.size[1], im.size[0]
typ, extra = _MODE_CONV[im.mode]
if extra is None:
return shape, typ
else:
return shape+(extra,), typ
MODES = list(_MODEINFO.keys())
MODES.sort()
# 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")
##
# 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.
# @return "L" or "RGB".
# @exception KeyError If the input mode was not a standard mode.
def getmodebase(mode):
return ImageMode.getmode(mode).basemode
##
# Gets the storage type mode. Given a mode, this function returns a
# single-layer mode suitable for storing individual bands.
#
# @param mode Input mode.
# @return "L", "I", or "F".
# @exception KeyError If the input mode was not a standard mode.
def getmodetype(mode):
return ImageMode.getmode(mode).basetype
##
# Gets a list of individual band names. Given a mode, this function
# returns a tuple containing the names of individual bands (use
# {@link #getmodetype} to get the mode used to store each individual
# band.
#
# @param mode Input mode.
# @return 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.
def getmodebandnames(mode):
return ImageMode.getmode(mode).bands
##
# Gets the number of individual bands for this mode.
#
# @param mode Input mode.
# @return The number of bands in this mode.
# @exception KeyError If the input mode was not a standard mode.
def getmodebands(mode):
return len(ImageMode.getmode(mode).bands)
# --------------------------------------------------------------------
# Helpers
_initialized = 0
##
# Explicitly loads standard file format drivers.
def preinit():
"Load standard file format drivers."
global _initialized
if _initialized >= 1:
return
try:
import BmpImagePlugin
except ImportError:
pass
try:
import GifImagePlugin
except ImportError:
pass
try:
import JpegImagePlugin
except ImportError:
pass
try:
import PpmImagePlugin
except ImportError:
pass
try:
import PngImagePlugin
except ImportError:
pass
# try:
# import TiffImagePlugin
# except ImportError:
# pass
_initialized = 1
##
# Explicitly initializes the Python Imaging Library. This function
# loads all available file format drivers.
def init():
"Load all file format drivers."
global _initialized
if _initialized >= 2:
return 0
visited = {}
directories = sys.path
try:
directories = directories + [os.path.dirname(__file__)]
except NameError:
pass
# only check directories (including current, if present in the path)
for directory in filter(isDirectory, directories):
fullpath = os.path.abspath(directory)
if fullpath in visited:
continue
for file in os.listdir(directory):
if file[-14:] == "ImagePlugin.py":
f, e = os.path.splitext(file)
try:
sys.path.insert(0, directory)
try:
__import__(f, globals(), locals(), [])
finally:
del sys.path[0]
except ImportError:
if DEBUG:
print "Image: failed to import",
print f, ":", sys.exc_info()[1]
visited[fullpath] = None
if OPEN or SAVE:
_initialized = 2
return 1
# --------------------------------------------------------------------
# Codec factories (used by tostring/fromstring and ImageFile.load)
def _getdecoder(mode, decoder_name, args, extra=()):
# tweak arguments
if args is None:
args = ()
elif not isTupleType(args):
args = (args,)
try:
# get decoder
decoder = getattr(core, decoder_name + "_decoder")
# print decoder, (mode,) + args + extra
return apply(decoder, (mode,) + args + extra)
except AttributeError:
raise IOError("decoder %s not available" % decoder_name)
def _getencoder(mode, encoder_name, args, extra=()):
# tweak arguments
if args is None:
args = ()
elif not isTupleType(args):
args = (args,)
try:
# get encoder
encoder = getattr(core, encoder_name + "_encoder")
# print encoder, (mode,) + args + extra
return apply(encoder, (mode,) + args + extra)
except AttributeError:
raise IOError("encoder %s not available" % encoder_name)
# --------------------------------------------------------------------
# Simple expression analyzer
class _E:
def __init__(self, data): self.data = data
def __coerce__(self, other): return self, _E(other)
def __add__(self, other): return _E((self.data, "__add__", other.data))
def __mul__(self, other): return _E((self.data, "__mul__", 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 isNumberType(c)):
return c, 0.0
if (a is stub and b == "__add__" and isNumberType(c)):
return 1.0, c
except TypeError: pass
try:
((a, b, c), d, e) = data # full syntax
if (a is stub and b == "__mul__" and isNumberType(c) and
d == "__add__" and isNumberType(e)):
return c, e
except TypeError: pass
raise ValueError("illegal expression")
# --------------------------------------------------------------------
# Implementation wrapper
##
# This class represents an image object. To create Image objects, use
# the appropriate factory functions. There's hardly ever any reason
# to call the Image constructor directly.
#
# @see #open
# @see #new
# @see #fromstring
class Image:
format = None
format_description = None
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 = NORMAL
self.readonly = 0
def _new(self, im):
new = Image()
new.im = im
new.mode = im.mode
new.size = im.size
new.palette = self.palette
if im.mode == "P":
new.palette = ImagePalette.ImagePalette()
try:
new.info = self.info.copy()
except AttributeError:
# fallback (pre-1.5.2)
new.info = {}
for k, v in self.info:
new.info[k] = v
return new
_makeself = _new # compatibility
def _copy(self):
self.load()
self.im = self.im.copy()
self.readonly = 0
def _dump(self, file=None, format=None):
import tempfile
if not file:
file = tempfile.mktemp()
self.load()
if not format or format == "PPM":
self.im.save_ppm(file)
else:
file = file + "." + format
self.save(file, format)
return file
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 __getattr__(self, name):
if name == "__array_interface__":
# numpy array interface support
new = {}
shape, typestr = _conv_type_shape(self)
new['shape'] = shape
new['typestr'] = typestr
new['data'] = self.tostring()
return new
raise AttributeError(name)
##
# Returns a string containing pixel data.
#
# @param encoder_name What encoder to use. The default is to
# use the standard "raw" encoder.
# @param *args Extra arguments to the encoder.
# @return An 8-bit string.
def tostring(self, encoder_name="raw", *args):
"Return image as a binary string"
# may pass tuple instead of argument list
if len(args) == 1 and isTupleType(args[0]):
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 1:
l, s, d = e.encode(bufsize)
data.append(d)
if s:
break
if s < 0:
raise RuntimeError("encoder error %d in tostring" % s)
return "".join(data)
##
# Returns the image converted to an X11 bitmap. This method
# only works for mode "1" images.
#
# @param name The name prefix to use for the bitmap variables.
# @return A string containing an X11 bitmap.
# @exception ValueError If the mode is not "1"
def tobitmap(self, name="image"):
"Return image as an XBM bitmap"
self.load()
if self.mode != "1":
raise ValueError("not a bitmap")
data = self.tostring("xbm")
return "".join(["#define %s_width %d\n" % (name, self.size[0]),
"#define %s_height %d\n"% (name, self.size[1]),
"static char %s_bits[] = {\n" % name, data, "};"])
##
# Loads this image with pixel data from a string.
# <p>
# This method is similar to the {@link #fromstring} function, but
# loads data into this image instead of creating a new image
# object.
def fromstring(self, data, decoder_name="raw", *args):
"Load data to image from binary string"
# may pass tuple instead of argument list
if len(args) == 1 and isTupleType(args[0]):
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")
##
# 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.
#
# @return An image access object.
def load(self):
"Explicitly load pixel data."
if self.im and self.palette and self.palette.dirty:
# realize palette
apply(self.im.putpalette, self.palette.getdata())
self.palette.dirty = 0
self.palette.mode = "RGB"
self.palette.rawmode = None
if "transparency" in self.info:
self.im.putpalettealpha(self.info["transparency"], 0)
self.palette.mode = "RGBA"
if self.im:
return self.im.pixel_access(self.readonly)
##
# 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.
def verify(self):
"Verify file contents."
pass
##
# 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.
# <p>
# The current version supports all possible conversions between
# "L", "RGB" and "CMYK."
# <p>
# When translating a colour image to black and white (mode "L"),
# the library uses the ITU-R 601-2 luma transform:
# <p>
# <b>L = R * 299/1000 + G * 587/1000 + B * 114/1000</b>
# <p>
# When translating a greyscale image into a bilevel image (mode
# "1"), all non-zero values are set to 255 (white). To use other
# thresholds, use the {@link #Image.point} method.
#
# @def convert(mode, matrix=None, **options)
# @param mode The requested mode.
# @param matrix An optional conversion matrix. If given, this
# should be 4- or 16-tuple containing floating point values.
# @param options Additional options, given as keyword arguments.
# @keyparam dither Dithering method, used when converting from
# mode "RGB" to "P".
# Available methods are NONE or FLOYDSTEINBERG (default).
# @keyparam palette Palette to use when converting from mode "RGB"
# to "P". Available palettes are WEB or ADAPTIVE.
# @keyparam colors Number of colors to use for the ADAPTIVE palette.
# Defaults to 256.
# @return An Image object.
def convert(self, mode=None, data=None, dither=None,
palette=WEB, colors=256):
"Convert to other pixel format"
if not mode:
# determine default mode
if self.mode == "P":
self.load()
if self.palette:
mode = self.palette.mode
else:
mode = "RGB"
else:
return self.copy()
self.load()
if data:
# matrix conversion
if mode not in ("L", "RGB"):
raise ValueError("illegal conversion")
im = self.im.convert_matrix(mode, data)
return self._new(im)
if mode == "P" and palette == ADAPTIVE:
im = self.im.quantize(colors)
return self._new(im)
# colourspace 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:
raise ValueError("illegal conversion")
return self._new(im)
def quantize(self, colors=256, method=0, kmeans=0, palette=None):
# methods:
# 0 = median cut
# 1 = maximum coverage
# NOTE: this functionality will be moved to the extended
# quantizer interface in a later version of PIL.
self.load()
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", 1, palette.im)
return self._makeself(im)
im = self.im.quantize(colors, method, kmeans)
return self._new(im)
##
# Copies this image. Use this method if you wish to paste things
# into an image, but still retain the original.
#
# @return An Image object.
def copy(self):
"Copy raster data"
self.load()
im = self.im.copy()
return self._new(im)
##
# Returns a rectangular region from this image. The box is a
# 4-tuple defining the left, upper, right, and lower pixel
# coordinate.
# <p>
# This is a lazy operation. Changes to the source image may or
# may not be reflected in the cropped image. To break the
# connection, call the {@link #Image.load} method on the cropped
# copy.
#
# @param The crop rectangle, as a (left, upper, right, lower)-tuple.
# @return An Image object.
def crop(self, box=None):
"Crop region from image"
self.load()
if box is None:
return self.copy()
# lazy operation
return _ImageCrop(self, box)
##
# 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 colour
# JPEG to greyscale while loading it, or to extract a 128x192
# version from a PCD file.
# <p>
# Note that this method modifies the Image object in place. If
# the image has already been loaded, this method has no effect.
#
# @param mode The requested mode.
# @param size The requested size.
def draft(self, mode, size):
"Configure image decoder"
pass
def _expand(self, xmargin, ymargin=None):
if ymargin is None:
ymargin = xmargin
self.load()
return self._new(self.im.expand(xmargin, ymargin, 0))
##
# Filters this image using the given filter. For a list of
# available filters, see the <b>ImageFilter</b> module.
#
# @param filter Filter kernel.
# @return An Image object.
# @see ImageFilter
def filter(self, filter):
"Apply environment filter to image"
self.load()
if isinstance(filter, collections.Callable):
filter = filter()
if not hasattr(filter, "filter"):
raise TypeError("filter argument should be ImageFilter.Filter instance or class")
if self.im.bands == 1:
return self._new(filter.filter(self.im))
# fix to handle multiband images since _imaging doesn't
ims = []
for c in range(self.im.bands):
ims.append(self._new(filter.filter(self.im.getband(c))))
return merge(self.mode, ims)
##
# Returns a tuple containing the name of each band in this image.
# For example, <b>getbands</b> on an RGB image returns ("R", "G", "B").
#
# @return A tuple containing band names.
def getbands(self):
"Get band names"
return ImageMode.getmode(self.mode).bands
##
# Calculates the bounding box of the non-zero regions in the
# image.
#
# @return The bounding box is returned as a 4-tuple defining the
# left, upper, right, and lower pixel coordinate. If the image
# is completely empty, this method returns None.
def getbbox(self):
"Get bounding box of actual data (non-zero pixels) in image"
self.load()
return self.im.getbbox()
##
# Returns a list of colors used in this image.
#
# @param maxcolors Maximum number of colors. If this number is
# exceeded, this method returns None. The default limit is
# 256 colors.
# @return An unsorted list of (count, pixel) values.
def getcolors(self, maxcolors=256):
"Get colors from image, up to given limit"
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)
##
# 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.
# <p>
# 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 <b>list(im.getdata())</b>.
#
# @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).
# @return A sequence-like object.
def getdata(self, band = None):
"Get image data as sequence object."
self.load()
if band is not None:
return self.im.getband(band)
return self.im # could be abused
##
# Gets the the minimum and maximum pixel values for each band in
# the image.
#
# @return 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.
def getextrema(self):
"Get min/max value"
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()
##
# Returns a capsule that points to the internal image memory.
#
# @return A capsule object.
def getim(self):
"Get capsule pointer to internal image memory"
self.load()
return self.im.ptr
##
# Returns the image palette as a list.
#
# @return A list of color values [r, g, b, ...], or None if the
# image has no palette.
def getpalette(self):
"Get palette contents."
self.load()
try:
return [ord(c) for c in self.im.getpalette()]
except ValueError:
return None # no palette
##
# Returns the pixel value at a given position.
#
# @param xy The coordinate, given as (x, y).
# @return The pixel value. If the image is a multi-layer image,
# this method returns a tuple.
def getpixel(self, xy):
"Get pixel value"
self.load()
return self.im.getpixel(xy)
##
# Returns the horizontal and vertical projection.
#
# @return Two sequences, indicating where there are non-zero
# pixels along the X-axis and the Y-axis, respectively.
def getprojection(self):
"Get projection to x and y axes"
self.load()
x, y = self.im.getprojection()
return [ord(c) for c in x], [ord(c) for c in y]
##
# 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).
# <p>
# A bilevel image (mode "1") is treated as a greyscale ("L") image
# by this method.
# <p>
# 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").
#
# @def histogram(mask=None)
# @param mask An optional mask.
# @return A list containing pixel counts.
def histogram(self, mask=None, extrema=None):
"Take histogram of image"
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()
##
# (Deprecated) Returns a copy of the image where the data has been
# offset by the given distances. Data wraps around the edges. If
# yoffset is omitted, it is assumed to be equal to xoffset.
# <p>
# This method is deprecated. New code should use the <b>offset</b>
# function in the <b>ImageChops</b> module.
#
# @param xoffset The horizontal distance.
# @param yoffset The vertical distance. If omitted, both
# distances are set to the same value.
# @return An Image object.
def offset(self, xoffset, yoffset=None):
"(deprecated) Offset image in horizontal and/or vertical direction"
if warnings:
warnings.warn(
"'offset' is deprecated; use 'ImageChops.offset' instead",
DeprecationWarning, stacklevel=2
)
import ImageChops
return ImageChops.offset(self, xoffset, yoffset)
##
# 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)). If a 4-tuple is given, the size of the pasted image
# must match the size of the region.
# <p>
# If the modes don't match, the pasted image is converted to the
# mode of this image (see the {@link #Image.convert} method for
# details).
# <p>
# Instead of an image, the source can be a integer or tuple
# containing pixel values. The method then fills the region
# with the given colour. When creating RGB images, you can
# also use colour strings as supported by the ImageColor module.
# <p>
# 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 can be used for transparency effects.
# <p>
# Note that if you paste an "RGBA" image, the alpha band is
# ignored. You can work around this by using the same image as
# both source image and mask.
#
# @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.
# <p>
# 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.
# @return An Image object.
def paste(self, im, box=None, mask=None):
"Paste other image into region"
if isImageType(box) and mask is None:
# abbreviated paste(im, mask) syntax
mask = box; box = None
if box is None:
# cover all of self
box = (0, 0) + self.size
if len(box) == 2:
# lower 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 + (box[0]+size[0], box[1]+size[1])
if isStringType(im):
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.load()
if self.readonly:
self._copy()
if mask:
mask.load()
self.im.paste(im, box, mask.im)
else:
self.im.paste(im, box)
##
# Maps this image through a lookup table or function.
#
# @param lut A lookup table, containing 256 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.
# @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".
# @return An Image object.
def point(self, lut, mode=None):
"Map image through lookup table"
self.load()
if isinstance(lut, ImagePointHandler):
return lut.point(self)
if not isSequenceType(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
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))
##
# 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 im 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.
def putalpha(self, alpha):
"Set alpha layer"
self.load()
if self.readonly:
self._copy()
if self.mode not in ("LA", "RGBA"):
# attempt to promote self to a matching alpha mode
try:
mode = getmodebase(self.mode) + "A"
try:
self.im.setmode(mode)
except (AttributeError, ValueError):
# do things the hard way
im = self.im.convert(mode)
if im.mode not in ("LA", "RGBA"):
raise ValueError # sanity check
self.im = im
self.mode = self.im.mode
except (KeyError, ValueError):
raise ValueError("illegal image mode")
if self.mode == "LA":
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)
##
# 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: <b>pixel = value*scale + offset</b>.
#
# @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.
def putdata(self, data, scale=1.0, offset=0.0):
"Put data from a sequence object into an image."
self.load()
if self.readonly:
self._copy()
self.im.putdata(data, scale, offset)
##
# Attaches a palette to this image. The image must be a "P" or
# "L" image, and the palette sequence must contain 768 integer
# values, where each group of three values represent the red,
# green, and blue values for the corresponding pixel
# index. Instead of an integer sequence, you can use an 8-bit
# string.
#
# @def putpalette(data)
# @param data A palette sequence (either a list or a string).
def putpalette(self, data, rawmode="RGB"):
"Put palette data into an image."
if self.mode not in ("L", "P"):
raise ValueError("illegal image mode")
self.load()
if isinstance(data, ImagePalette.ImagePalette):
palette = ImagePalette.raw(data.rawmode, data.palette)
else:
if not isStringType(data):
data = "".join(map(chr, data))
palette = ImagePalette.raw(rawmode, data)
self.mode = "P"
self.palette = palette
self.palette.mode = "RGB"
self.load() # install new palette
##
# Modifies the pixel at the given position. The colour is given as
# a single numerical value for single-band images, and a tuple for
# multi-band images.
# <p>
# Note that this method is relatively slow. For more extensive
# changes, use {@link #Image.paste} or the <b>ImageDraw</b> module
# instead.
#
# @param xy The pixel coordinate, given as (x, y).
# @param value The pixel value.
# @see #Image.paste
# @see #Image.putdata
# @see ImageDraw
def putpixel(self, xy, value):
"Set pixel value"
self.load()
if self.readonly:
self._copy()
return self.im.putpixel(xy, value)
##
# Returns a resized copy of this image.
#
# @def resize(size, filter=NEAREST)
# @param size The requested size in pixels, as a 2-tuple:
# (width, height).
# @param filter An optional resampling filter. This can be
# one of <b>NEAREST</b> (use nearest neighbour), <b>BILINEAR</b>
# (linear interpolation in a 2x2 environment), <b>BICUBIC</b>
# (cubic spline interpolation in a 4x4 environment), or
# <b>ANTIALIAS</b> (a high-quality downsampling filter).
# If omitted, or if the image has mode "1" or "P", it is
# set <b>NEAREST</b>.
# @return An Image object.
def resize(self, size, resample=NEAREST):
"Resize image"
if resample not in (NEAREST, BILINEAR, BICUBIC, ANTIALIAS):
raise ValueError("unknown resampling filter")
self.load()
if self.mode in ("1", "P"):
resample = NEAREST
if resample == ANTIALIAS:
# requires stretch support (imToolkit & PIL 1.1.3)
try:
im = self.im.stretch(size, resample)
except AttributeError:
raise ValueError("unsupported resampling filter")
else:
im = self.im.resize(size, resample)
return self._new(im)
##
# 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.
#
# @def rotate(angle, filter=NEAREST)
# @param angle In degrees counter clockwise.
# @param filter An optional resampling filter. This can be
# one of <b>NEAREST</b> (use nearest neighbour), <b>BILINEAR</b>
# (linear interpolation in a 2x2 environment), or <b>BICUBIC</b>
# (cubic spline interpolation in a 4x4 environment).
# If omitted, or if the image has mode "1" or "P", it is
# set <b>NEAREST</b>.
# @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.
# @return An Image object.
def rotate(self, angle, resample=NEAREST, expand=0):
"Rotate image. Angle given as degrees counter-clockwise."
if expand:
import math
angle = -angle * math.pi / 180
matrix = [
math.cos(angle), math.sin(angle), 0.0,
-math.sin(angle), math.cos(angle), 0.0
]
def transform(x, y, (a, b, c, d, e, f)=matrix):
return a*x + b*y + c, d*x + e*y + f
# calculate output size
w, h = self.size
xx = []
yy = []
for x, y in ((0, 0), (w, 0), (w, h), (0, h)):
x, y = transform(x, y)
xx.append(x)
yy.append(y)
w = int(math.ceil(max(xx)) - math.floor(min(xx)))
h = int(math.ceil(max(yy)) - math.floor(min(yy)))
# adjust center
x, y = transform(w / 2.0, h / 2.0)
matrix[2] = self.size[0] / 2.0 - x
matrix[5] = self.size[1] / 2.0 - y
return self.transform((w, h), AFFINE, matrix, resample)
if resample not in (NEAREST, BILINEAR, BICUBIC):
raise ValueError("unknown resampling filter")
self.load()
if self.mode in ("1", "P"):
resample = NEAREST
return self._new(self.im.rotate(angle, resample))
##
# Saves this image under the given filename. If no format is
# specified, the format to use is determined from the filename
# extension, if possible.
# <p>
# 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 later in
# this handbook.
# <p>
# 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 <b>seek</b>, <b>tell</b>, and <b>write</b>
# methods, and be opened in binary mode.
#
# @def save(file, format=None, **options)
# @param file File name 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 **options Extra parameters to the image writer.
# @return None
# @exception KeyError If the output format could not be determined
# from the file name. Use the format option to solve this.
# @exception IOError If the file could not be written. The file
# may have been created, and may contain partial data.
def save(self, fp, format=None, **params):
"Save image to file or stream"
if isStringType(fp):
filename = fp
else:
if hasattr(fp, "name") and isStringType(fp.name):
filename = fp.name
else:
filename = ""
# may mutate self!
self.load()
self.encoderinfo = params
self.encoderconfig = ()
preinit()
ext = os.path.splitext(filename)[1].lower()
if not format:
try:
format = EXTENSION[ext]
except KeyError:
init()
try:
format = EXTENSION[ext]
except KeyError:
raise KeyError(ext) # unknown extension
try:
save_handler = SAVE[format.upper()]
except KeyError:
init()
save_handler = SAVE[format.upper()] # unknown format
if isStringType(fp):
import __builtin__
fp = __builtin__.open(fp, "wb")
close = 1
else:
close = 0
try:
save_handler(self, fp, filename)
finally:
# do what we can to clean up
if close:
fp.close()
##
# Seeks to the given frame in this sequence file. If you seek
# beyond the end of the sequence, the method raises an
# <b>EOFError</b> exception. When a sequence file is opened, the
# library automatically seeks to frame 0.
# <p>
# Note that in the current version of the library, most sequence
# formats only allows you to seek to the next frame.
#
# @param frame Frame number, starting at 0.
# @exception EOFError If the call attempts to seek beyond the end
# of the sequence.
# @see #Image.tell
def seek(self, frame):
"Seek to given frame in sequence file"
# overridden by file handlers
if frame != 0:
raise EOFError
##
# Displays this image. This method is mainly intended for
# debugging purposes.
# <p>
# On Unix platforms, this method saves the image to a temporary
# PPM file, and calls the <b>xv</b> utility.
# <p>
# On Windows, it saves the image to a temporary BMP file, and uses
# the standard BMP display utility to show it (usually Paint).
#
# @def show(title=None)
# @param title Optional title to use for the image window,
# where possible.
def show(self, title=None, command=None):
"Display image (for debug purposes only)"
_show(self, title=title, command=command)
##
# 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).
#
# @return A tuple containing bands.
def split(self):
"Split image into bands"
self.load()
if self.im.bands == 1:
ims = [self.copy()]
else:
ims = []
for i in range(self.im.bands):
ims.append(self._new(self.im.getband(i)))
return tuple(ims)
##
# Returns the current frame number.
#
# @return Frame number, starting with 0.
# @see #Image.seek
def tell(self):
"Return current frame number"
return 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 {@link
# #Image.draft} method to configure the file reader (where
# applicable), and finally resizes the image.
# <p>
# Note that the bilinear and bicubic filters in the current
# version of PIL are not well-suited for thumbnail generation.
# You should use <b>ANTIALIAS</b> unless speed is much more
# important than quality.
# <p>
# Also note that this function modifies the Image object in place.
# If you need to use the full resolution image as well, apply this
# method to a {@link #Image.copy} of the original image.
#
# @param size Requested size.
# @param resample Optional resampling filter. This can be one
# of <b>NEAREST</b>, <b>BILINEAR</b>, <b>BICUBIC</b>, or
# <b>ANTIALIAS</b> (best quality). If omitted, it defaults
# to <b>NEAREST</b> (this will be changed to ANTIALIAS in a
# future version).
# @return None
def thumbnail(self, size, resample=NEAREST):
"Create thumbnail representation (modifies image in place)"
# FIXME: the default resampling filter will be changed
# to ANTIALIAS in future versions
# preserve aspect ratio
x, y = self.size
if x > size[0]: y = int(max(y * size[0] / x, 1)); x = int(size[0])
if y > size[1]: x = int(max(x * size[1] / y, 1)); y = int(size[1])
size = x, y
if size == self.size:
return
self.draft(None, size)
self.load()
try:
im = self.resize(size, resample)
except ValueError:
if resample != ANTIALIAS:
raise
im = self.resize(size, NEAREST) # fallback
self.im = im.im
self.mode = im.mode
self.size = size
self.readonly = 0
# FIXME: the different tranform methods need further explanation
# instead of bloating the method docs, add a separate chapter.
##
# 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.
# <p>
# @def transform(size, method, data, resample=NEAREST)
# @param size The output size.
# @param method The transformation method. This is one of
# <b>EXTENT</b> (cut out a rectangular subregion), <b>AFFINE</b>
# (affine transform), <b>PERSPECTIVE</b> (perspective
# transform), <b>QUAD</b> (map a quadrilateral to a
# rectangle), or <b>MESH</b> (map a number of source quadrilaterals
# in one operation).
# @param data Extra data to the transformation method.
# @param resample Optional resampling filter. It can be one of
# <b>NEAREST</b> (use nearest neighbour), <b>BILINEAR</b>
# (linear interpolation in a 2x2 environment), or
# <b>BICUBIC</b> (cubic spline interpolation in a 4x4
# environment). If omitted, or if the image has mode
# "1" or "P", it is set to <b>NEAREST</b>.
# @return An Image object.
def transform(self, size, method, data=None, resample=NEAREST, fill=1):
"Transform image"
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, None)
if method == MESH:
# list of quads
for box, quad in data:
im.__transformer(box, self, QUAD, quad, resample, fill)
else:
im.__transformer((0, 0)+size, self, method, data, resample, fill)
return im
def __transformer(self, box, image, method, data,
resample=NEAREST, fill=1):
# FIXME: this should be turned into a lazy operation (?)
w = box[2]-box[0]
h = box[3]-box[1]
if method == AFFINE:
# change argument order to match implementation
data = (data[2], data[0], data[1],
data[5], data[3], data[4])
elif method == EXTENT:
# convert extent to an affine transform
x0, y0, x1, y1 = data
xs = float(x1 - x0) / w
ys = float(y1 - y0) / h
method = AFFINE
data = (x0 + xs/2, xs, 0, y0 + ys/2, 0, ys)
elif method == PERSPECTIVE:
# change argument order to match implementation
data = (data[2], data[0], data[1],
data[5], data[3], data[4],
data[6], data[7])
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):
raise ValueError("unknown resampling filter")
image.load()
self.load()
if image.mode in ("1", "P"):
resample = NEAREST
self.im.transform2(box, image.im, method, data, resample, fill)
##
# Returns a flipped or rotated copy of this image.
#
# @param method One of <b>FLIP_LEFT_RIGHT</b>, <b>FLIP_TOP_BOTTOM</b>,
# <b>ROTATE_90</b>, <b>ROTATE_180</b>, or <b>ROTATE_270</b>.
def transpose(self, method):
"Transpose image (flip or rotate in 90 degree steps)"
self.load()
im = self.im.transpose(method)
return self._new(im)
# --------------------------------------------------------------------
# Lazy operations
class _ImageCrop(Image):
def __init__(self, im, box):
Image.__init__(self)
x0, y0, x1, y1 = box
if x1 < x0:
x1 = x0
if y1 < y0:
y1 = y0
self.mode = im.mode
self.size = x1-x0, y1-y0
self.__crop = x0, y0, x1, y1
self.im = im.im
def load(self):
# lazy evaluation!
if self.__crop:
self.im = self.im.crop(self.__crop)
self.__crop = None
if self.im:
return self.im.pixel_access(self.readonly)
# FIXME: future versions should optimize crop/paste
# sequences!
# --------------------------------------------------------------------
# Abstract handlers.
class ImagePointHandler:
# used as a mixin by point transforms (for use with im.point)
pass
class ImageTransformHandler:
# used as a mixin by geometry transforms (for use with im.transform)
pass
# --------------------------------------------------------------------
# Factories
#
# Debugging
def _wedge():
"Create greyscale wedge (for debugging only)"
return Image()._new(core.wedge("L"))
##
# Creates a new image with the given mode and size.
#
# @param mode The mode to use for the new image.
# @param size A 2-tuple, containing (width, height) in pixels.
# @param color What colour 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 colour
# strings as supported by the ImageColor module. If the colour is
# None, the image is not initialised.
# @return An Image object.
def new(mode, size, color=0):
"Create a new image"
if color is None:
# don't initialize
return Image()._new(core.new(mode, size))
if isStringType(color):
# css3-style specifier
import ImageColor
color = ImageColor.getcolor(color, mode)
return Image()._new(core.fill(mode, size, color))
##
# Creates an image memory from pixel data in a string.
# <p>
# In its simplest form, this function takes three arguments
# (mode, size, and unpacked pixel data).
# <p>
# You can also use any pixel decoder supported by PIL. For more
# information on available decoders, see the section <a
# href="pil-decoder.htm"><i>Writing Your Own File Decoder</i></a>.
# <p>
# Note that this function decodes pixel data only, not entire images.
# If you have an entire image in a string, wrap it in a
# <b>StringIO</b> object, and use {@link #open} to load it.
#
# @param mode The image mode.
# @param size The image size.
# @param data An 8-bit string containing raw data for the given mode.
# @param decoder_name What decoder to use.
# @param *args Additional parameters for the given decoder.
# @return An Image object.
def fromstring(mode, size, data, decoder_name="raw", *args):
"Load image from string"
# may pass tuple instead of argument list
if len(args) == 1 and isTupleType(args[0]):
args = args[0]
if decoder_name == "raw" and args == ():
args = mode
im = new(mode, size)
im.fromstring(data, decoder_name, args)
return im
##
# (New in 1.1.4) Creates an image memory from pixel data in a string
# or byte buffer.
# <p>
# This function is similar to {@link #fromstring}, 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".
# <p>
# 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
# <b>StringIO</b> object, and use {@link #open} to load it.
# <p>
# In the current version, the default parameters used for the "raw"
# decoder differs from that used for {@link fromstring}. 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.
# @param size The image size.
# @param data An 8-bit string 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:
# <b>frombuffer(mode, size, data, "raw", mode, 0, 1)</b>.
# @return An Image object.
# @since 1.1.4
def frombuffer(mode, size, data, decoder_name="raw", *args):
"Load image from string or buffer"
# may pass tuple instead of argument list
if len(args) == 1 and isTupleType(args[0]):
args = args[0]
if decoder_name == "raw":
if args == ():
if warnings:
warnings.warn(
"the frombuffer defaults may change in a future release; "
"for portability, change the call to read:\n"
" frombuffer(mode, size, data, 'raw', mode, 0, 1)",
RuntimeWarning, stacklevel=2
)
args = mode, 0, -1 # may change to (mode, 0, 1) post-1.1.6
if args[0] in _MAPMODES:
im = new(mode, (1,1))
im = im._new(
core.map_buffer(data, size, decoder_name, None, 0, args)
)
im.readonly = 1
return im
return fromstring(mode, size, data, decoder_name, args)
##
# (New in 1.1.6) Creates an image memory from an object exporting
# the array interface (using the buffer protocol).
#
# If obj is not contiguous, then the tostring method is called
# and {@link frombuffer} is used.
#
# @param obj Object with array interface
# @param mode Mode to use (will be determined from type if None)
# @return An image memory.
def fromarray(obj, mode=None):
arr = obj.__array_interface__
shape = arr['shape']
ndim = len(shape)
try:
strides = arr['strides']
except KeyError:
strides = None
if mode is None:
try:
typekey = (1, 1) + shape[2:], arr['typestr']
mode, rawmode = _fromarray_typemap[typekey]
except KeyError:
# print typekey
raise TypeError("Cannot handle this data type")
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("Too many dimensions.")
size = shape[1], shape[0]
if strides is not None:
obj = obj.tostring()
return frombuffer(mode, size, obj, "raw", rawmode, 0, 1)
_fromarray_typemap = {
# (shape, typestr) => mode, rawmode
# first two members of shape are set to one
# ((1, 1), "|b1"): ("1", "1"), # broken
((1, 1), "|u1"): ("L", "L"),
((1, 1), "|i1"): ("I", "I;8"),
((1, 1), "<i2"): ("I", "I;16"),
((1, 1), ">i2"): ("I", "I;16B"),
((1, 1), "<i4"): ("I", "I;32"),
((1, 1), ">i4"): ("I", "I;32B"),
((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, 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")
##
# Opens and identifies the given image file.
# <p>
# This is a lazy operation; this function identifies the file, but the
# actual image data is not read from the file until you try to process
# the data (or call the {@link #Image.load} method).
#
# @def open(file, mode="r")
# @param file A filename (string) or a file object. The file object
# must implement <b>read</b>, <b>seek</b>, and <b>tell</b> methods,
# and be opened in binary mode.
# @param mode The mode. If given, this argument must be "r".
# @return An Image object.
# @exception IOError If the file cannot be found, or the image cannot be
# opened and identified.
# @see #new
def open(fp, mode="r"):
"Open an image file, without loading the raster data"
if mode != "r":
raise ValueError("bad mode")
if isStringType(fp):
import __builtin__
filename = fp
fp = __builtin__.open(fp, "rb")
else:
filename = ""
prefix = fp.read(16)
preinit()
for i in ID:
try:
factory, accept = OPEN[i]
if not accept or accept(prefix):
fp.seek(0)
return factory(fp, filename)
except (SyntaxError, IndexError, TypeError):
pass
if init():
for i in ID:
try:
factory, accept = OPEN[i]
if not accept or accept(prefix):
fp.seek(0)
return factory(fp, filename)
except (SyntaxError, IndexError, TypeError):
pass
raise IOError("cannot identify image file")
#
# Image processing.
##
# Alpha composites im2 over im1.
#
# @param im1 The first image.
# @param im2 The second image. Must have the same mode and size as
# the first image.
# @return An Image object.
def alpha_composite(im1, im2):
"Alpha composite im2 over im1."
im1.load()
im2.load()
return im1._new(core.alpha_composite(im1.im, im2.im))
##
# Creates a new image by interpolating between two input images, using
# a constant alpha.
#
# <pre>
# out = image1 * (1.0 - alpha) + image2 * alpha
# </pre>
#
# @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.
# @return An Image object.
def blend(im1, im2, alpha):
"Interpolate between images."
im1.load()
im2.load()
return im1._new(core.blend(im1.im, im2.im, alpha))
##
# Creates a new image by interpolating between two input images,
# using the mask as alpha.
#
# @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 can have mode
# "1", "L", or "RGBA", and must have the same size as the
# other two images.
def composite(image1, image2, mask):
"Create composite image by blending images using a transparency mask"
image = image2.copy()
image.paste(image1, None, mask)
return image
##
# 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.
#
# @def eval(image, function)
# @param image The input image.
# @param function A function object, taking one integer argument.
# @return An Image object.
def eval(image, *args):
"Evaluate image expression"
return image.point(args[0])
##
# Creates a new image from a number of single-band images.
#
# @param mode The mode to use for the output image.
# @param bands A sequence containing one single-band image for
# each band in the output image. All bands must have the
# same size.
# @return An Image object.
def merge(mode, bands):
"Merge a set of single band images into a new multiband image."
if getmodebands(mode) != len(bands) or "*" in mode:
raise ValueError("wrong number of bands")
for im in bands[1:]:
if im.mode != getmodetype(mode):
raise ValueError("mode mismatch")
if im.size != bands[0].size:
raise ValueError("size mismatch")
im = core.new(mode, bands[0].size)
for i in range(getmodebands(mode)):
bands[i].load()
im.putband(bands[i].im, i)
return bands[0]._new(im)
# --------------------------------------------------------------------
# Plugin registry
##
# 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.
def register_open(id, factory, accept=None):
id = id.upper()
ID.append(id)
OPEN[id] = factory, accept
##
# 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.
def register_mime(id, mimetype):
MIME[id.upper()] = mimetype
##
# 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.
def register_save(id, driver):
SAVE[id.upper()] = driver
##
# 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.
def register_extension(id, extension):
EXTENSION[extension.lower()] = id.upper()
# --------------------------------------------------------------------
# Simple display support. User code may override this.
def _show(image, **options):
# override me, as necessary
apply(_showxv, (image,), options)
def _showxv(image, title=None, **options):
import ImageShow
apply(ImageShow.show, (image, title), options)
Reference in New Issue View Git Blame Copy Permalink