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# Source code for PIL.McIdasImagePlugin

    #
    # The Python Imaging Library.
    # $Id$
    #
    # Basic McIdas support for PIL
    #
    # History:
    # 1997-05-05 fl  Created (8-bit images only)
    # 2009-03-08 fl  Added 16/32-bit support.
    #
    # Thanks to Richard Jones and Craig Swank for specs and samples.
    #
    # Copyright (c) Secret Labs AB 1997.
    # Copyright (c) Fredrik Lundh 1997.
    #
    # See the README file for information on usage and redistribution.
    #
    from __future__ import annotations

    import struct

    from . import Image, ImageFile

    def _accept(prefix: bytes) -> bool:
        return prefix.startswith(b"\x00\x00\x00\x00\x00\x00\x00\x04")

    ##
    # Image plugin for McIdas area images.

    class McIdasImageFile(ImageFile.ImageFile):
        format = "MCIDAS"
        format_description = "McIdas area file"

        def _open(self) -> None:
            # parse area file directory
            assert self.fp is not None

            s = self.fp.read(256)
            if not _accept(s) or len(s) != 256:
                msg = "not an McIdas area file"
                raise SyntaxError(msg)

            self.area_descriptor_raw = s
            self.area_descriptor = w = [0, *struct.unpack("!64i", s)]

            # get mode
            if w[11] == 1:
                mode = rawmode = "L"
            elif w[11] == 2:
                mode = rawmode = "I;16B"
            elif w[11] == 4:
                # FIXME: add memory map support
                mode = "I"
                rawmode = "I;32B"
            else:
                msg = "unsupported McIdas format"
                raise SyntaxError(msg)

            self._mode = mode
            self._size = w[10], w[9]

            offset = w[34] + w[15]
            stride = w[15] + w[10] * w[11] * w[14]

            self.tile = [
                ImageFile._Tile("raw", (0, 0) + self.size, offset, (rawmode, stride, 1))
            ]

    # --------------------------------------------------------------------
    # registry

    Image.register_open(McIdasImageFile.format, McIdasImageFile, _accept)

    # no default extension