Viewing file:  SunImagePlugin.py (4.39 KB) -rw-r--r--
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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 __future__ import annotations
from . import Image, ImageFile, ImagePalette
from ._binary import i32be as i32
def _accept(prefix: bytes) -> bool:
return len(prefix) >= 4 and i32(prefix) == 0x59A66A95
##
# Image plugin for Sun raster files.
class SunImageFile(ImageFile.ImageFile):
format = "SUN"
format_description = "Sun Raster File"
def _open(self) -> None:
# 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;
assert self.fp is not None
# HEAD
s = self.fp.read(32)
if not _accept(s):
msg = "not an SUN raster file"
raise SyntaxError(msg)
offset = 32
self._size = i32(s, 4), i32(s, 8)
depth = i32(s, 12)
# data_length = i32(s, 16) # unreliable, ignore.
file_type = i32(s, 20)
palette_type = i32(s, 24) # 0: None, 1: RGB, 2: Raw/arbitrary
palette_length = i32(s, 28)
if depth == 1:
self._mode, rawmode = "1", "1;I"
elif depth == 4:
self._mode, rawmode = "L", "L;4"
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"
else:
msg = "Unsupported Mode/Bit Depth"
raise SyntaxError(msg)
if palette_length:
if palette_length > 1024:
msg = "Unsupported Color Palette Length"
raise SyntaxError(msg)
if palette_type != 1:
msg = "Unsupported Palette Type"
raise SyntaxError(msg)
offset = offset + palette_length
self.palette = ImagePalette.raw("RGB;L", self.fp.read(palette_length))
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
# 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.
# (https://www.fileformat.info/format/sunraster/egff.htm)
if file_type in (0, 1, 3, 4, 5):
self.tile = [("raw", (0, 0) + self.size, offset, (rawmode, stride))]
elif file_type == 2:
self.tile = [("sun_rle", (0, 0) + self.size, offset, rawmode)]
else:
msg = "Unsupported Sun Raster file type"
raise SyntaxError(msg)
#
# registry
Image.register_open(SunImageFile.format, SunImageFile, _accept)
Image.register_extension(SunImageFile.format, ".ras")
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