Pillow/PIL/GdImageFile.py
2013-01-10 08:46:50 -06:00

91 lines
2.1 KiB
Python

#
# The Python Imaging Library.
# $Id$
#
# GD file handling
#
# History:
# 1996-04-12 fl Created
#
# Copyright (c) 1997 by Secret Labs AB.
# Copyright (c) 1996 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
# NOTE: This format cannot be automatically recognized, so the
# class is not registered for use with Image.open(). To open a
# gd file, use the GdImageFile.open() function instead.
# THE GD FORMAT IS NOT DESIGNED FOR DATA INTERCHANGE. This
# implementation is provided for convenience and demonstrational
# purposes only.
__version__ = "0.1"
from . import ImageFile, ImagePalette
try:
import builtins
except ImportError:
import __builtin__
builtins = __builtin__
def i16(c):
return ord(c[1]) + (ord(c[0])<<8)
##
# Image plugin for the GD uncompressed format. Note that this format
# is not supported by the standard <b>Image.open</b> function. To use
# this plugin, you have to import the <b>GdImageFile</b> module and
# use the <b>GdImageFile.open</b> function.
class GdImageFile(ImageFile.ImageFile):
format = "GD"
format_description = "GD uncompressed images"
def _open(self):
# Header
s = self.fp.read(775)
self.mode = "L" # FIXME: "P"
self.size = i16(s[0:2]), i16(s[2:4])
# transparency index
tindex = i16(s[5:7])
if tindex < 256:
self.info["transparent"] = tindex
self.palette = ImagePalette.raw("RGB", s[7:])
self.tile = [("raw", (0,0)+self.size, 775, ("L", 0, -1))]
##
# Load texture from a GD image file.
#
# @param filename GD file name, or an opened file handle.
# @param mode Optional mode. In this version, if the mode argument
# is given, it must be "r".
# @return An image instance.
# @exception IOError If the image could not be read.
def open(fp, mode = "r"):
if mode != "r":
raise ValueError("bad mode")
if type(fp) == type(""):
filename = fp
fp = builtins.open(fp, "rb")
else:
filename = ""
try:
return GdImageFile(fp, filename)
except SyntaxError:
raise IOError("cannot identify this image file")