Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/spst/UnixTransition/doc/ImagePaletteH.py Дата изменения: Fri Feb 28 14:46:08 2014 Дата индексирования: Sat Mar 1 16:38:23 2014 Кодировка:

#
# The Python Imaging Library.
# $Id: ImagePalette.py,v 1.1 1998/05/14 21:34:58 friedric Exp friedric $
#
# image palette object
#
# History:
# 96-03-11 fl Rewritten.
# 97-01-03 fl Up and running.
# 97-08-23 fl Added load hack
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1996-97.
#
# See the README file for information on usage and redistribution.
#
try:
import array
jpython = 0
except ImportError:
import jarray
jpython = 1
import ImageH

class ImagePalette:
"Colour palette for palette mapped images"

def __init__(self, mode = "RGB", palette = None):
self.mode = mode
self.palette = palette or range(256)*len(self.mode)
if len(self.mode)*256 != len(self.palette):
raise ValueError, "wrong palette size"

def tostring(self):
if jpython == 0:
return array.array("b", self.palette).tostring()
else:
return jarray.array(self.palette, "b").tostring()


def save(self, fp):
if type(fp) == type(""):
fp = open(fp, "w")
fp.write("# Palette\n")
fp.write("# Mode: %s\n" % self.mode)
for i in range(256):
fp.write("%d" % i)
for j in range(i, len(self.palette), 256):
fp.write(" %d" % self.palette[j])
fp.write("\n")
fp.close()

# --------------------------------------------------------------------
# Internal

class raw:
def __init__(self, rawmode, data):
self.rawmode = rawmode
self.data = data

# --------------------------------------------------------------------
# Factories

def new(mode, data):
ImageH.core.new_palette(mode, data)

def negative(mode = "RGB"):
palette = range(256)
palette.reverse()
return ImagePalette(mode, palette * len(mode))

def random(mode = "RGB"):
from whrandom import randint
palette = map(lambda a: randint(0, 255), [0]*256*len(mode))
return ImagePalette(mode, palette)

def wedge(mode = "RGB"):
return ImagePalette(mode, range(256) * len(mode))

def load(filename):

# FIXME: supports GIMP gradients only

fp = open(filename, "rb")

lut = None

if not lut:
try:
import GimpPaletteFile
fp.seek(0)
p = GimpPaletteFile.GimpPaletteFile(fp)
lut = p.getpalette()
except (SyntaxError, ValueError):
pass

if not lut:
try:
import GimpGradientFile
fp.seek(0)
p = GimpGradientFile.GimpGradientFile(fp)
lut = p.getpalette()
except (SyntaxError, ValueError):
pass

if not lut:
try:
import PaletteFile
fp.seek(0)
p = PaletteFile.PaletteFile(fp)
lut = p.getpalette()
except (SyntaxError, ValueError):
pass

if not lut:
raise IOError, "cannot load palette"

return lut # data, rawmode


# add some psuedocolour palettes as well