codekingpro/portable-devtools
114k
1#
2# The Python Imaging Library.
3# $Id$
4#
5# TGA file handling
6#
7# History:
8# 95-09-01 fl created (reads 24-bit files only)
9# 97-01-04 fl support more TGA versions, including compressed images
10# 98-07-04 fl fixed orientation and alpha layer bugs
11# 98-09-11 fl fixed orientation for runlength decoder
12#
13# Copyright (c) Secret Labs AB 1997-98.
14# Copyright (c) Fredrik Lundh 1995-97.
15#
16# See the README file for information on usage and redistribution.
17#
18from __future__ import annotations
19
20import os
21import warnings
22from typing import IO
23
24from . import Image, ImageFile, ImagePalette
25from ._binary import i16le as i16
26from ._binary import i32le as i32
27from ._binary import o8
28from ._binary import o16le as o16
29
30#
31# --------------------------------------------------------------------
32# Read RGA file
33
34
35MODES = {
36 # map imagetype/depth to rawmode
37 (1, 8): "P",
38 (3, 1): "1",
39 (3, 8): "L",
40 (3, 16): "LA",
41 (2, 16): "BGRA;15Z",
42 (2, 24): "BGR",
43 (2, 32): "BGRA",
44}
45
46
47##
48# Image plugin for Targa files.
49
50
51class TgaImageFile(ImageFile.ImageFile):
52 format = "TGA"
53 format_description = "Targa"
54
55 def _open(self) -> None:
56 # process header
57 assert self.fp is not None
58
59 s = self.fp.read(18)
60
61 id_len = s[0]
62
63 colormaptype = s[1]
64 imagetype = s[2]
65
66 depth = s[16]
67
68 flags = s[17]
69
70 self._size = i16(s, 12), i16(s, 14)
71
72 # validate header fields
73 if (
74 colormaptype not in (0, 1)
75 or self.size[0] <= 0
76 or self.size[1] <= 0
77 or depth not in (1, 8, 16, 24, 32)
78 ):
79 msg = "not a TGA file"
80 raise SyntaxError(msg)
81
82 # image mode
83 if imagetype in (3, 11):
84 self._mode = "L"
85 if depth == 1:
86 self._mode = "1" # ???
87 elif depth == 16:
88 self._mode = "LA"
89 elif imagetype in (1, 9):
90 self._mode = "P" if colormaptype else "L"
91 elif imagetype in (2, 10):
92 self._mode = "RGB" if depth == 24 else "RGBA"
93 else:
94 msg = "unknown TGA mode"
95 raise SyntaxError(msg)
96
97 # orientation
98 orientation = flags & 0x30
99 self._flip_horizontally = orientation in [0x10, 0x30]
100 if orientation in [0x20, 0x30]:
101 orientation = 1
102 elif orientation in [0, 0x10]:
103 orientation = -1
104 else:
105 msg = "unknown TGA orientation"
106 raise SyntaxError(msg)
107
108 self.info["orientation"] = orientation
109
110 if imagetype & 8:
111 self.info["compression"] = "tga_rle"
112
113 if id_len:
114 self.info["id_section"] = self.fp.read(id_len)
115
116 if colormaptype:
117 # read palette
118 start, size, mapdepth = i16(s, 3), i16(s, 5), s[7]
119 if mapdepth == 16:
120 self.palette = ImagePalette.raw(
121 "BGRA;15Z", bytes(2 * start) + self.fp.read(2 * size)
122 )
123 self.palette.mode = "RGBA"
124 elif mapdepth == 24:
125 self.palette = ImagePalette.raw(
126 "BGR", bytes(3 * start) + self.fp.read(3 * size)
127 )
128 elif mapdepth == 32:
129 self.palette = ImagePalette.raw(
130 "BGRA", bytes(4 * start) + self.fp.read(4 * size)
131 )
132 else:
133 msg = "unknown TGA map depth"
134 raise SyntaxError(msg)
135
136 # setup tile descriptor
137 try:
138 rawmode = MODES[(imagetype & 7, depth)]
139 if imagetype & 8:
140 # compressed
141 self.tile = [
142 ImageFile._Tile(
143 "tga_rle",
144 (0, 0) + self.size,
145 self.fp.tell(),
146 (rawmode, orientation, depth),
147 )
148 ]
149 else:
150 self.tile = [
151 ImageFile._Tile(
152 "raw",
153 (0, 0) + self.size,
154 self.fp.tell(),
155 (rawmode, 0, orientation),
156 )
157 ]
158 except KeyError:
159 pass # cannot decode
160
161 def load_end(self) -> None:
162 if self.mode == "RGBA":
163 assert self.fp is not None
164 self.fp.seek(-26, os.SEEK_END)
165 footer = self.fp.read(26)
166 if footer.endswith(b"TRUEVISION-XFILE.\x00"):
167 # version 2
168 extension_offset = i32(footer)
169 if extension_offset:
170 self.fp.seek(extension_offset + 494)
171 attributes_type = self.fp.read(1)
172 if attributes_type == b"\x00":
173 # No alpha
174 self.im.fillband(3, 255)
175
176 if self._flip_horizontally:
177 self.im = self.im.transpose(Image.Transpose.FLIP_LEFT_RIGHT)
178
179
180#
181# --------------------------------------------------------------------
182# Write TGA file
183
184
185SAVE = {
186 "1": ("1", 1, 0, 3),
187 "L": ("L", 8, 0, 3),
188 "LA": ("LA", 16, 0, 3),
189 "P": ("P", 8, 1, 1),
190 "RGB": ("BGR", 24, 0, 2),
191 "RGBA": ("BGRA", 32, 0, 2),
192}
193
194
195def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
196 try:
197 rawmode, bits, colormaptype, imagetype = SAVE[im.mode]
198 except KeyError as e:
199 msg = f"cannot write mode {im.mode} as TGA"
200 raise OSError(msg) from e
201
202 if "rle" in im.encoderinfo:
203 rle = im.encoderinfo["rle"]
204 else:
205 compression = im.encoderinfo.get("compression", im.info.get("compression"))
206 rle = compression == "tga_rle"
207 if rle:
208 imagetype += 8
209
210 id_section = im.encoderinfo.get("id_section", im.info.get("id_section", ""))
211 id_len = len(id_section)
212 if id_len > 255:
213 id_len = 255
214 id_section = id_section[:255]
215 warnings.warn("id_section has been trimmed to 255 characters")
216
217 if colormaptype:
218 palette = im.im.getpalette("RGB", "BGR")
219 colormaplength, colormapentry = len(palette) // 3, 24
220 else:
221 colormaplength, colormapentry = 0, 0
222
223 if im.mode in ("LA", "RGBA"):
224 flags = 8
225 else:
226 flags = 0
227
228 orientation = im.encoderinfo.get("orientation", im.info.get("orientation", -1))
229 if orientation > 0:
230 flags = flags | 0x20
231
232 fp.write(
233 o8(id_len)
234 + o8(colormaptype)
235 + o8(imagetype)
236 + o16(0) # colormapfirst
237 + o16(colormaplength)
238 + o8(colormapentry)
239 + o16(0)
240 + o16(0)
241 + o16(im.size[0])
242 + o16(im.size[1])
243 + o8(bits)
244 + o8(flags)
245 )
246
247 if id_section:
248 fp.write(id_section)
249
250 if colormaptype:
251 fp.write(palette)
252
253 if rle:
254 ImageFile._save(
255 im,
256 fp,
257 [ImageFile._Tile("tga_rle", (0, 0) + im.size, 0, (rawmode, orientation))],
258 )
259 else:
260 ImageFile._save(
261 im,
262 fp,
263 [ImageFile._Tile("raw", (0, 0) + im.size, 0, (rawmode, 0, orientation))],
264 )
265
266 # write targa version 2 footer
267 fp.write(b"\000" * 8 + b"TRUEVISION-XFILE." + b"\000")
268
269
270#
271# --------------------------------------------------------------------
272# Registry
273
274
275Image.register_open(TgaImageFile.format, TgaImageFile)
276Image.register_save(TgaImageFile.format, _save)
277
278Image.register_extensions(TgaImageFile.format, [".tga", ".icb", ".vda", ".vst"])
279
280Image.register_mime(TgaImageFile.format, "image/x-tga")
281