Coverage for /var/srv/projects/api.amasfac.comuna18.com/tmp/venv/lib/python3.9/site-packages/PIL/PpmImagePlugin.py: 12%
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« prev ^ index » next coverage.py v6.4.4, created at 2023-07-17 14:22 -0600
1#
2# The Python Imaging Library.
3# $Id$
4#
5# PPM support for PIL
6#
7# History:
8# 96-03-24 fl Created
9# 98-03-06 fl Write RGBA images (as RGB, that is)
10#
11# Copyright (c) Secret Labs AB 1997-98.
12# Copyright (c) Fredrik Lundh 1996.
13#
14# See the README file for information on usage and redistribution.
15#
18from . import Image, ImageFile
19from ._binary import i16be as i16
20from ._binary import o8
21from ._binary import o32le as o32
23#
24# --------------------------------------------------------------------
26b_whitespace = b"\x20\x09\x0a\x0b\x0c\x0d"
28MODES = {
29 # standard
30 b"P1": "1",
31 b"P2": "L",
32 b"P3": "RGB",
33 b"P4": "1",
34 b"P5": "L",
35 b"P6": "RGB",
36 # extensions
37 b"P0CMYK": "CMYK",
38 # PIL extensions (for test purposes only)
39 b"PyP": "P",
40 b"PyRGBA": "RGBA",
41 b"PyCMYK": "CMYK",
42}
45def _accept(prefix):
46 return prefix[0:1] == b"P" and prefix[1] in b"0123456y"
49##
50# Image plugin for PBM, PGM, and PPM images.
53class PpmImageFile(ImageFile.ImageFile):
55 format = "PPM"
56 format_description = "Pbmplus image"
58 def _read_magic(self):
59 magic = b""
60 # read until whitespace or longest available magic number
61 for _ in range(6):
62 c = self.fp.read(1)
63 if not c or c in b_whitespace:
64 break
65 magic += c
66 return magic
68 def _read_token(self):
69 token = b""
70 while len(token) <= 10: # read until next whitespace or limit of 10 characters
71 c = self.fp.read(1)
72 if not c:
73 break
74 elif c in b_whitespace: # token ended
75 if not token:
76 # skip whitespace at start
77 continue
78 break
79 elif c == b"#":
80 # ignores rest of the line; stops at CR, LF or EOF
81 while self.fp.read(1) not in b"\r\n":
82 pass
83 continue
84 token += c
85 if not token:
86 # Token was not even 1 byte
87 raise ValueError("Reached EOF while reading header")
88 elif len(token) > 10:
89 raise ValueError(f"Token too long in file header: {token.decode()}")
90 return token
92 def _open(self):
93 magic_number = self._read_magic()
94 try:
95 mode = MODES[magic_number]
96 except KeyError:
97 raise SyntaxError("not a PPM file")
99 if magic_number in (b"P1", b"P4"):
100 self.custom_mimetype = "image/x-portable-bitmap"
101 elif magic_number in (b"P2", b"P5"):
102 self.custom_mimetype = "image/x-portable-graymap"
103 elif magic_number in (b"P3", b"P6"):
104 self.custom_mimetype = "image/x-portable-pixmap"
106 maxval = None
107 decoder_name = "raw"
108 if magic_number in (b"P1", b"P2", b"P3"):
109 decoder_name = "ppm_plain"
110 for ix in range(3):
111 token = int(self._read_token())
112 if ix == 0: # token is the x size
113 xsize = token
114 elif ix == 1: # token is the y size
115 ysize = token
116 if mode == "1":
117 self.mode = "1"
118 rawmode = "1;I"
119 break
120 else:
121 self.mode = rawmode = mode
122 elif ix == 2: # token is maxval
123 maxval = token
124 if not 0 < maxval < 65536:
125 raise ValueError(
126 "maxval must be greater than 0 and less than 65536"
127 )
128 if maxval > 255 and mode == "L":
129 self.mode = "I"
131 if decoder_name != "ppm_plain":
132 # If maxval matches a bit depth, use the raw decoder directly
133 if maxval == 65535 and mode == "L":
134 rawmode = "I;16B"
135 elif maxval != 255:
136 decoder_name = "ppm"
138 args = (rawmode, 0, 1) if decoder_name == "raw" else (rawmode, maxval)
139 self._size = xsize, ysize
140 self.tile = [(decoder_name, (0, 0, xsize, ysize), self.fp.tell(), args)]
143#
144# --------------------------------------------------------------------
147class PpmPlainDecoder(ImageFile.PyDecoder):
148 _pulls_fd = True
150 def _read_block(self):
151 return self.fd.read(ImageFile.SAFEBLOCK)
153 def _find_comment_end(self, block, start=0):
154 a = block.find(b"\n", start)
155 b = block.find(b"\r", start)
156 return min(a, b) if a * b > 0 else max(a, b) # lowest nonnegative index (or -1)
158 def _ignore_comments(self, block):
159 if self._comment_spans:
160 # Finish current comment
161 while block:
162 comment_end = self._find_comment_end(block)
163 if comment_end != -1:
164 # Comment ends in this block
165 # Delete tail of comment
166 block = block[comment_end + 1 :]
167 break
168 else:
169 # Comment spans whole block
170 # So read the next block, looking for the end
171 block = self._read_block()
173 # Search for any further comments
174 self._comment_spans = False
175 while True:
176 comment_start = block.find(b"#")
177 if comment_start == -1:
178 # No comment found
179 break
180 comment_end = self._find_comment_end(block, comment_start)
181 if comment_end != -1:
182 # Comment ends in this block
183 # Delete comment
184 block = block[:comment_start] + block[comment_end + 1 :]
185 else:
186 # Comment continues to next block(s)
187 block = block[:comment_start]
188 self._comment_spans = True
189 break
190 return block
192 def _decode_bitonal(self):
193 """
194 This is a separate method because in the plain PBM format, all data tokens are
195 exactly one byte, so the inter-token whitespace is optional.
196 """
197 data = bytearray()
198 total_bytes = self.state.xsize * self.state.ysize
200 while len(data) != total_bytes:
201 block = self._read_block() # read next block
202 if not block:
203 # eof
204 break
206 block = self._ignore_comments(block)
208 tokens = b"".join(block.split())
209 for token in tokens:
210 if token not in (48, 49):
211 raise ValueError(f"Invalid token for this mode: {bytes([token])}")
212 data = (data + tokens)[:total_bytes]
213 invert = bytes.maketrans(b"01", b"\xFF\x00")
214 return data.translate(invert)
216 def _decode_blocks(self, maxval):
217 data = bytearray()
218 max_len = 10
219 out_byte_count = 4 if self.mode == "I" else 1
220 out_max = 65535 if self.mode == "I" else 255
221 bands = Image.getmodebands(self.mode)
222 total_bytes = self.state.xsize * self.state.ysize * bands * out_byte_count
224 half_token = False
225 while len(data) != total_bytes:
226 block = self._read_block() # read next block
227 if not block:
228 if half_token:
229 block = bytearray(b" ") # flush half_token
230 else:
231 # eof
232 break
234 block = self._ignore_comments(block)
236 if half_token:
237 block = half_token + block # stitch half_token to new block
239 tokens = block.split()
241 if block and not block[-1:].isspace(): # block might split token
242 half_token = tokens.pop() # save half token for later
243 if len(half_token) > max_len: # prevent buildup of half_token
244 raise ValueError(
245 f"Token too long found in data: {half_token[:max_len + 1]}"
246 )
248 for token in tokens:
249 if len(token) > max_len:
250 raise ValueError(
251 f"Token too long found in data: {token[:max_len + 1]}"
252 )
253 value = int(token)
254 if value > maxval:
255 raise ValueError(f"Channel value too large for this mode: {value}")
256 value = round(value / maxval * out_max)
257 data += o32(value) if self.mode == "I" else o8(value)
258 if len(data) == total_bytes: # finished!
259 break
260 return data
262 def decode(self, buffer):
263 self._comment_spans = False
264 if self.mode == "1":
265 data = self._decode_bitonal()
266 rawmode = "1;8"
267 else:
268 maxval = self.args[-1]
269 data = self._decode_blocks(maxval)
270 rawmode = "I;32" if self.mode == "I" else self.mode
271 self.set_as_raw(bytes(data), rawmode)
272 return -1, 0
275class PpmDecoder(ImageFile.PyDecoder):
276 _pulls_fd = True
278 def decode(self, buffer):
279 data = bytearray()
280 maxval = self.args[-1]
281 in_byte_count = 1 if maxval < 256 else 2
282 out_byte_count = 4 if self.mode == "I" else 1
283 out_max = 65535 if self.mode == "I" else 255
284 bands = Image.getmodebands(self.mode)
285 while len(data) < self.state.xsize * self.state.ysize * bands * out_byte_count:
286 pixels = self.fd.read(in_byte_count * bands)
287 if len(pixels) < in_byte_count * bands:
288 # eof
289 break
290 for b in range(bands):
291 value = (
292 pixels[b] if in_byte_count == 1 else i16(pixels, b * in_byte_count)
293 )
294 value = min(out_max, round(value / maxval * out_max))
295 data += o32(value) if self.mode == "I" else o8(value)
296 rawmode = "I;32" if self.mode == "I" else self.mode
297 self.set_as_raw(bytes(data), rawmode)
298 return -1, 0
301#
302# --------------------------------------------------------------------
305def _save(im, fp, filename):
306 if im.mode == "1":
307 rawmode, head = "1;I", b"P4"
308 elif im.mode == "L":
309 rawmode, head = "L", b"P5"
310 elif im.mode == "I":
311 rawmode, head = "I;16B", b"P5"
312 elif im.mode in ("RGB", "RGBA"):
313 rawmode, head = "RGB", b"P6"
314 else:
315 raise OSError(f"cannot write mode {im.mode} as PPM")
316 fp.write(head + b"\n%d %d\n" % im.size)
317 if head == b"P6":
318 fp.write(b"255\n")
319 elif head == b"P5":
320 if rawmode == "L":
321 fp.write(b"255\n")
322 else:
323 fp.write(b"65535\n")
324 ImageFile._save(im, fp, [("raw", (0, 0) + im.size, 0, (rawmode, 0, 1))])
326 # ALTERNATIVE: save via builtin debug function
327 # im._dump(filename)
330#
331# --------------------------------------------------------------------
334Image.register_open(PpmImageFile.format, PpmImageFile, _accept)
335Image.register_save(PpmImageFile.format, _save)
337Image.register_decoder("ppm", PpmDecoder)
338Image.register_decoder("ppm_plain", PpmPlainDecoder)
340Image.register_extensions(PpmImageFile.format, [".pbm", ".pgm", ".ppm", ".pnm"])
342Image.register_mime(PpmImageFile.format, "image/x-portable-anymap")