codekingpro/portable-devtools

1#
2# The Python Imaging Library.
3# $Id$
4#
5# Sun image file handling
6#
7# History:
8# 1995-09-10 fl   Created
9# 1996-05-28 fl   Fixed 32-bit alignment
10# 1998-12-29 fl   Import ImagePalette module
11# 2001-12-18 fl   Fixed palette loading (from Jean-Claude Rimbault)
12#
13# Copyright (c) 1997-2001 by Secret Labs AB
14# Copyright (c) 1995-1996 by Fredrik Lundh
15#
16# See the README file for information on usage and redistribution.
17#
18from __future__ import annotations
19
20from . import Image, ImageFile, ImagePalette
21from ._binary import i32be as i32
22
23
24def _accept(prefix: bytes) -> bool:
25    return len(prefix) >= 4 and i32(prefix) == 0x59A66A95
26
27
28##
29# Image plugin for Sun raster files.
30
31
32class SunImageFile(ImageFile.ImageFile):
33    format = "SUN"
34    format_description = "Sun Raster File"
35
36    def _open(self) -> None:
37        # The Sun Raster file header is 32 bytes in length
38        # and has the following format:
39
40        #     typedef struct _SunRaster
41        #     {
42        #         DWORD MagicNumber;      /* Magic (identification) number */
43        #         DWORD Width;            /* Width of image in pixels */
44        #         DWORD Height;           /* Height of image in pixels */
45        #         DWORD Depth;            /* Number of bits per pixel */
46        #         DWORD Length;           /* Size of image data in bytes */
47        #         DWORD Type;             /* Type of raster file */
48        #         DWORD ColorMapType;     /* Type of color map */
49        #         DWORD ColorMapLength;   /* Size of the color map in bytes */
50        #     } SUNRASTER;
51
52        assert self.fp is not None
53
54        # HEAD
55        s = self.fp.read(32)
56        if not _accept(s):
57            msg = "not an SUN raster file"
58            raise SyntaxError(msg)
59
60        offset = 32
61
62        self._size = i32(s, 4), i32(s, 8)
63
64        depth = i32(s, 12)
65        # data_length = i32(s, 16)   # unreliable, ignore.
66        file_type = i32(s, 20)
67        palette_type = i32(s, 24)  # 0: None, 1: RGB, 2: Raw/arbitrary
68        palette_length = i32(s, 28)
69
70        if depth == 1:
71            self._mode, rawmode = "1", "1;I"
72        elif depth == 4:
73            self._mode, rawmode = "L", "L;4"
74        elif depth == 8:
75            self._mode = rawmode = "L"
76        elif depth == 24:
77            if file_type == 3:
78                self._mode, rawmode = "RGB", "RGB"
79            else:
80                self._mode, rawmode = "RGB", "BGR"
81        elif depth == 32:
82            if file_type == 3:
83                self._mode, rawmode = "RGB", "RGBX"
84            else:
85                self._mode, rawmode = "RGB", "BGRX"
86        else:
87            msg = "Unsupported Mode/Bit Depth"
88            raise SyntaxError(msg)
89
90        if palette_length:
91            if palette_length > 1024:
92                msg = "Unsupported Color Palette Length"
93                raise SyntaxError(msg)
94
95            if palette_type != 1:
96                msg = "Unsupported Palette Type"
97                raise SyntaxError(msg)
98
99            offset = offset + palette_length
100            self.palette = ImagePalette.raw("RGB;L", self.fp.read(palette_length))
101            if self.mode == "L":
102                self._mode = "P"
103                rawmode = rawmode.replace("L", "P")
104
105        # 16 bit boundaries on stride
106        stride = ((self.size[0] * depth + 15) // 16) * 2
107
108        # file type: Type is the version (or flavor) of the bitmap
109        # file. The following values are typically found in the Type
110        # field:
111        # 0000h Old
112        # 0001h Standard
113        # 0002h Byte-encoded
114        # 0003h RGB format
115        # 0004h TIFF format
116        # 0005h IFF format
117        # FFFFh Experimental
118
119        # Old and standard are the same, except for the length tag.
120        # byte-encoded is run-length-encoded
121        # RGB looks similar to standard, but RGB byte order
122        # TIFF and IFF mean that they were converted from T/IFF
123        # Experimental means that it's something else.
124        # (https://www.fileformat.info/format/sunraster/egff.htm)
125
126        if file_type in (0, 1, 3, 4, 5):
127            self.tile = [
128                ImageFile._Tile("raw", (0, 0) + self.size, offset, (rawmode, stride))
129            ]
130        elif file_type == 2:
131            self.tile = [
132                ImageFile._Tile("sun_rle", (0, 0) + self.size, offset, rawmode)
133            ]
134        else:
135            msg = "Unsupported Sun Raster file type"
136            raise SyntaxError(msg)
137
138
139#
140# registry
141
142
143Image.register_open(SunImageFile.format, SunImageFile, _accept)
144
145Image.register_extension(SunImageFile.format, ".ras")
146