Pillow/PIL/SunImagePlugin.py

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#
# The Python Imaging Library.
# $Id$
#
# Sun image file handling
#
# History:
# 1995-09-10 fl Created
# 1996-05-28 fl Fixed 32-bit alignment
# 1998-12-29 fl Import ImagePalette module
# 2001-12-18 fl Fixed palette loading (from Jean-Claude Rimbault)
#
# Copyright (c) 1997-2001 by Secret Labs AB
# Copyright (c) 1995-1996 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#
from . import Image, ImageFile, ImagePalette
from ._binary import i32be as i32
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__version__ = "0.3"
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def _accept(prefix):
return len(prefix) >= 4 and i32(prefix) == 0x59a66a95
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##
# Image plugin for Sun raster files.
class SunImageFile(ImageFile.ImageFile):
format = "SUN"
format_description = "Sun Raster File"
def _open(self):
# The Sun Raster file header is 32 bytes in length and has the following format:
# typedef struct _SunRaster
# {
# DWORD MagicNumber; /* Magic (identification) number */
# DWORD Width; /* Width of image in pixels */
# DWORD Height; /* Height of image in pixels */
# DWORD Depth; /* Number of bits per pixel */
# DWORD Length; /* Size of image data in bytes */
# DWORD Type; /* Type of raster file */
# DWORD ColorMapType; /* Type of color map */
# DWORD ColorMapLength; /* Size of the color map in bytes */
# } SUNRASTER;
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# HEAD
s = self.fp.read(32)
if i32(s) != 0x59a66a95:
raise SyntaxError("not an SUN raster file")
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offset = 32
self.size = i32(s[4:8]), i32(s[8:12])
depth = i32(s[12:16])
data_length = i32(s[16:20]) # unreliable, ignore.
file_type = i32(s[20:24])
palette_type = i32(s[24:28]) # 0: None, 1: RGB, 2: Raw/arbitrary
palette_length = i32(s[28:32])
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if depth == 1:
self.mode, rawmode = "1", "1;I"
elif depth == 4:
self.mode, rawmode = "L", "L;4"
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elif depth == 8:
self.mode = rawmode = "L"
elif depth == 24:
if file_type == 3:
self.mode, rawmode = "RGB", "RGB"
else:
self.mode, rawmode = "RGB", "BGR"
elif depth == 32:
if file_type == 3:
self.mode, rawmode = 'RGB', 'RGBX'
else:
self.mode, rawmode = 'RGB', 'BGRX'
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else:
raise SyntaxError("Unsupported Mode/Bit Depth")
if palette_length:
if palette_length > 1024:
raise SyntaxError("Unsupported Color Palette Length")
if palette_type != 1:
raise SyntaxError("Unsupported Palette Type")
offset = offset + palette_length
self.palette = ImagePalette.raw("RGB;L", self.fp.read(palette_length))
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if self.mode == "L":
self.mode = "P"
rawmode = rawmode.replace('L', 'P')
# 16 bit boundaries on stride
stride = ((self.size[0] * depth + 15) // 16) * 2
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# file type: Type is the version (or flavor) of the bitmap
# file. The following values are typically found in the Type
# field:
# 0000h Old
# 0001h Standard
# 0002h Byte-encoded
# 0003h RGB format
# 0004h TIFF format
# 0005h IFF format
# FFFFh Experimental
# Old and standard are the same, except for the length tag.
# byte-encoded is run-length-encoded
# RGB looks similar to standard, but RGB byte order
# TIFF and IFF mean that they were converted from T/IFF
# Experimental means that it's something else.
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# (https://www.fileformat.info/format/sunraster/egff.htm)
if file_type in (0, 1, 3, 4, 5):
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self.tile = [("raw", (0, 0)+self.size, offset, (rawmode, stride))]
elif file_type == 2:
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self.tile = [("sun_rle", (0, 0)+self.size, offset, rawmode)]
else:
raise SyntaxError('Unsupported Sun Raster file type')
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#
# registry
Image.register_open(SunImageFile.format, SunImageFile, _accept)
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Image.register_extension(SunImageFile.format, ".ras")