XpmImagePlugin.py 4.3 KB

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  1. #
  2. # The Python Imaging Library.
  3. # $Id$
  4. #
  5. # XPM File handling
  6. #
  7. # History:
  8. # 1996-12-29 fl Created
  9. # 2001-02-17 fl Use 're' instead of 'regex' (Python 2.1) (0.7)
  10. #
  11. # Copyright (c) Secret Labs AB 1997-2001.
  12. # Copyright (c) Fredrik Lundh 1996-2001.
  13. #
  14. # See the README file for information on usage and redistribution.
  15. #
  16. from __future__ import annotations
  17. import re
  18. from . import Image, ImageFile, ImagePalette
  19. from ._binary import o8
  20. # XPM header
  21. xpm_head = re.compile(b'"([0-9]*) ([0-9]*) ([0-9]*) ([0-9]*)')
  22. def _accept(prefix: bytes) -> bool:
  23. return prefix.startswith(b"/* XPM */")
  24. ##
  25. # Image plugin for X11 pixel maps.
  26. class XpmImageFile(ImageFile.ImageFile):
  27. format = "XPM"
  28. format_description = "X11 Pixel Map"
  29. def _open(self) -> None:
  30. assert self.fp is not None
  31. if not _accept(self.fp.read(9)):
  32. msg = "not an XPM file"
  33. raise SyntaxError(msg)
  34. # skip forward to next string
  35. while True:
  36. line = self.fp.readline()
  37. if not line:
  38. msg = "broken XPM file"
  39. raise SyntaxError(msg)
  40. m = xpm_head.match(line)
  41. if m:
  42. break
  43. self._size = int(m.group(1)), int(m.group(2))
  44. palette_length = int(m.group(3))
  45. bpp = int(m.group(4))
  46. #
  47. # load palette description
  48. palette = {}
  49. for _ in range(palette_length):
  50. line = self.fp.readline().rstrip()
  51. c = line[1 : bpp + 1]
  52. s = line[bpp + 1 : -2].split()
  53. for i in range(0, len(s), 2):
  54. if s[i] == b"c":
  55. # process colour key
  56. rgb = s[i + 1]
  57. if rgb == b"None":
  58. self.info["transparency"] = c
  59. elif rgb.startswith(b"#"):
  60. rgb_int = int(rgb[1:], 16)
  61. palette[c] = (
  62. o8((rgb_int >> 16) & 255)
  63. + o8((rgb_int >> 8) & 255)
  64. + o8(rgb_int & 255)
  65. )
  66. else:
  67. # unknown colour
  68. msg = "cannot read this XPM file"
  69. raise ValueError(msg)
  70. break
  71. else:
  72. # missing colour key
  73. msg = "cannot read this XPM file"
  74. raise ValueError(msg)
  75. args: tuple[int, dict[bytes, bytes] | tuple[bytes, ...]]
  76. if palette_length > 256:
  77. self._mode = "RGB"
  78. args = (bpp, palette)
  79. else:
  80. self._mode = "P"
  81. self.palette = ImagePalette.raw("RGB", b"".join(palette.values()))
  82. args = (bpp, tuple(palette.keys()))
  83. self.tile = [ImageFile._Tile("xpm", (0, 0) + self.size, self.fp.tell(), args)]
  84. def load_read(self, read_bytes: int) -> bytes:
  85. #
  86. # load all image data in one chunk
  87. xsize, ysize = self.size
  88. assert self.fp is not None
  89. s = [self.fp.readline()[1 : xsize + 1].ljust(xsize) for i in range(ysize)]
  90. return b"".join(s)
  91. class XpmDecoder(ImageFile.PyDecoder):
  92. _pulls_fd = True
  93. def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]:
  94. assert self.fd is not None
  95. data = bytearray()
  96. bpp, palette = self.args
  97. dest_length = self.state.xsize * self.state.ysize
  98. if self.mode == "RGB":
  99. dest_length *= 3
  100. pixel_header = False
  101. while len(data) < dest_length:
  102. line = self.fd.readline()
  103. if not line:
  104. break
  105. if line.rstrip() == b"/* pixels */" and not pixel_header:
  106. pixel_header = True
  107. continue
  108. line = b'"'.join(line.split(b'"')[1:-1])
  109. for i in range(0, len(line), bpp):
  110. key = line[i : i + bpp]
  111. if self.mode == "RGB":
  112. data += palette[key]
  113. else:
  114. data += o8(palette.index(key))
  115. self.set_as_raw(bytes(data))
  116. return -1, 0
  117. #
  118. # Registry
  119. Image.register_open(XpmImageFile.format, XpmImageFile, _accept)
  120. Image.register_decoder("xpm", XpmDecoder)
  121. Image.register_extension(XpmImageFile.format, ".xpm")
  122. Image.register_mime(XpmImageFile.format, "image/xpm")