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  1. #
  2. # The Python Imaging Library.
  3. # $Id$
  4. #
  5. # Basic McIdas support for PIL
  6. #
  7. # History:
  8. # 1997-05-05 fl Created (8-bit images only)
  9. # 2009-03-08 fl Added 16/32-bit support.
  10. #
  11. # Thanks to Richard Jones and Craig Swank for specs and samples.
  12. #
  13. # Copyright (c) Secret Labs AB 1997.
  14. # Copyright (c) Fredrik Lundh 1997.
  15. #
  16. # See the README file for information on usage and redistribution.
  17. #
  18. import struct
  19. from . import Image, ImageFile
  20. __version__ = "0.2"
  21. def _accept(s):
  22. return s[:8] == b"\x00\x00\x00\x00\x00\x00\x00\x04"
  23. ##
  24. # Image plugin for McIdas area images.
  25. class McIdasImageFile(ImageFile.ImageFile):
  26. format = "MCIDAS"
  27. format_description = "McIdas area file"
  28. def _open(self):
  29. # parse area file directory
  30. s = self.fp.read(256)
  31. if not _accept(s) or len(s) != 256:
  32. raise SyntaxError("not an McIdas area file")
  33. self.area_descriptor_raw = s
  34. self.area_descriptor = w = [0] + list(struct.unpack("!64i", s))
  35. # get mode
  36. if w[11] == 1:
  37. mode = rawmode = "L"
  38. elif w[11] == 2:
  39. # FIXME: add memory map support
  40. mode = "I"
  41. rawmode = "I;16B"
  42. elif w[11] == 4:
  43. # FIXME: add memory map support
  44. mode = "I"
  45. rawmode = "I;32B"
  46. else:
  47. raise SyntaxError("unsupported McIdas format")
  48. self.mode = mode
  49. self._size = w[10], w[9]
  50. offset = w[34] + w[15]
  51. stride = w[15] + w[10]*w[11]*w[14]
  52. self.tile = [("raw", (0, 0) + self.size, offset, (rawmode, stride, 1))]
  53. # --------------------------------------------------------------------
  54. # registry
  55. Image.register_open(McIdasImageFile.format, McIdasImageFile, _accept)
  56. # no default extension