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pyqtgraph/PIL_Fix/Image.py
Luke Campagnola 3d84aefbc4 Initial commit (again)
2010-03-22 01:48:52 -04:00

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#
# The Python Imaging Library.
# $Id: Image.py 2933 2006-12-03 12:08:22Z fredrik $
#
# 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
#
# Copyright (c) 1997-2006 by Secret Labs AB. All rights reserved.
# Copyright (c) 1995-2006 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
VERSION = "1.1.6"
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
core = _imaging
del _imaging
except ImportError, 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, string, sys
# type stuff
from types import IntType, StringType, TupleType
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;16B, RGBa, BGR;15,
# and BGR;24. Use these modes only if you know exactly
# what you're doing...
}
if sys.byteorder == 'little':
_ENDIAN = '<'
else:
_ENDIAN = '>'
_MODE_CONV = {
# official modes
"1": ('|b1', None),
"L": ('|u1', None),
"I": ('%si4' % _ENDIAN, None), # FIXME: is this correct?
"I;16": ('%su2' % _ENDIAN, None), # FIXME: is this correct?
"F": ('%sf4' % _ENDIAN, None), # FIXME: is this correct?
"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]
typ, extra = _MODE_CONV[im.mode]
if extra is None:
return shape, typ
else:
return shape+(extra,), typ
MODES = _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;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
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 visited.has_key(fullpath):
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_value
visited[fullpath] = None
if OPEN or SAVE:
_initialized = 2
# --------------------------------------------------------------------
# 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):
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 __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 string.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 string.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 self.info.has_key("transparency"):
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)
# @param mode The requested mode.
# @param matrix An optional conversion matrix. If given, this
# should be 4- or 16-tuple containing floating point values.
# @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()
from ImageFilter import Filter
if not isinstance(filter, Filter):
filter = filter()
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 PyCObject that points to the internal image memory.
#
# @return A PyCObject object.
def getim(self):
"Get PyCObject 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 map(ord, 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 map(ord, x), map(ord, 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 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 = map(lut, 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."
self.load()
if self.mode not in ("L", "P"):
raise ValueError("illegal image mode")
if not isStringType(data):
data = string.join(map(chr, data), "")
self.mode = "P"
self.palette = ImagePalette.raw(rawmode, data)
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)
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 = string.lower(os.path.splitext(filename)[1])
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[string.upper(format)]
except KeyError:
init()
save_handler = SAVE[string.upper(format)] # 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)"
_showxv(self, title, 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"
ims = []
self.load()
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 = max(y * size[0] / x, 1); x = size[0]
if y > size[1]: x = max(x * size[1] / y, 1); y = 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"
import ImageTransform
if isinstance(method, ImageTransform.Transform):
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
# FIXME: future versions should optimize crop/paste
# sequences!
# --------------------------------------------------------------------
# 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 apply(fromstring, (mode, size, data, decoder_name, args))
##
# (New in 1.1.6) Create 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:
typestr = arr['typestr']
if not (typestr[0] == '|' or typestr[0] == _ENDIAN or
typestr[1:] not in ['u1', 'b1', 'i4', 'f4']):
raise TypeError("cannot handle data-type")
if typestr[0] == _ENDIAN:
typestr = typestr[1:3]
else:
typestr = typestr[:2]
if typestr == 'i4':
mode = 'I'
if typestr == 'u2':
mode = 'I;16'
elif typestr == 'f4':
mode = 'F'
elif typestr == 'b1':
mode = '1'
elif ndim == 2:
mode = 'L'
elif ndim == 3:
mode = 'RGB'
elif ndim == 4:
mode = 'RGBA'
else:
raise TypeError("Do not understand data.")
ndmax = 4
bad_dims=0
if mode in ['1','L','I','P','F']:
ndmax = 2
elif mode == 'RGB':
ndmax = 3
if ndim > ndmax:
raise ValueError("Too many dimensions.")
size = shape[:2][::-1]
if strides is not None:
obj = obj.tostring()
return frombuffer(mode, size, obj, "raw", mode, 0, 1)
##
# 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
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.
##
# 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 = string.upper(id)
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[string.upper(id)] = 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[string.upper(id)] = 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[string.lower(extension)] = string.upper(id)
# --------------------------------------------------------------------
# Simple display support
def _showxv(image, title=None, command=None):
if os.name == "nt":
format = "BMP"
elif sys.platform == "darwin":
format = "JPEG"
if not command:
command = "open -a /Applications/Preview.app"
else:
format = None
if not command:
command = "xv"
if title:
command = command + " -name \"%s\"" % title
if image.mode == "I;16":
# @PIL88 @PIL101
# "I;16" isn't an 'official' mode, but we still want to
# provide a simple way to show 16-bit images.
base = "L"
else:
base = getmodebase(image.mode)
if base != image.mode and image.mode != "1":
file = image.convert(base)._dump(format=format)
else:
file = image._dump(format=format)
if os.name == "nt":
command = "start /wait %s && del /f %s" % (file, file)
elif sys.platform == "darwin":
# on darwin open returns immediately resulting in the temp
# file removal while app is opening
command = "(%s %s; sleep 20; rm -f %s)&" % (command, file, file)
else:
command = "(%s %s; rm -f %s)&" % (command, file, file)
os.system(command)
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