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# Source code for PIL.GbrImagePlugin

    #
    # The Python Imaging Library
    #
    # load a GIMP brush file
    #
    # History:
    #       96-03-14 fl     Created
    #       16-01-08 es     Version 2
    #
    # Copyright (c) Secret Labs AB 1997.
    # Copyright (c) Fredrik Lundh 1996.
    # Copyright (c) Eric Soroos 2016.
    #
    # See the README file for information on usage and redistribution.
    #
    #
    # See https://github.com/GNOME/gimp/blob/mainline/devel-docs/gbr.txt for
    # format documentation.
    #
    # This code Interprets version 1 and 2 .gbr files.
    # Version 1 files are obsolete, and should not be used for new
    #   brushes.
    # Version 2 files are saved by GIMP v2.8 (at least)
    # Version 3 files have a format specifier of 18 for 16bit floats in
    #   the color depth field. This is currently unsupported by Pillow.
    from __future__ import annotations

    from . import Image, ImageFile
    from ._binary import i32be as i32

    def _accept(prefix: bytes) -> bool:
        return len(prefix) >= 8 and i32(prefix, 0) >= 20 and i32(prefix, 4) in (1, 2)

    ##
    # Image plugin for the GIMP brush format.

    class GbrImageFile(ImageFile.ImageFile):
        format = "GBR"
        format_description = "GIMP brush file"

        def _open(self) -> None:
            assert self.fp is not None
            header_size = i32(self.fp.read(4))
            if header_size < 20:
                msg = "not a GIMP brush"
                raise SyntaxError(msg)
            version = i32(self.fp.read(4))
            if version not in (1, 2):
                msg = f"Unsupported GIMP brush version: {version}"
                raise SyntaxError(msg)

            width = i32(self.fp.read(4))
            height = i32(self.fp.read(4))
            color_depth = i32(self.fp.read(4))
            if width == 0 or height == 0:
                msg = "not a GIMP brush"
                raise SyntaxError(msg)
            if color_depth not in (1, 4):
                msg = f"Unsupported GIMP brush color depth: {color_depth}"
                raise SyntaxError(msg)

            if version == 1:
                comment_length = header_size - 20
            else:
                comment_length = header_size - 28
                magic_number = self.fp.read(4)
                if magic_number != b"GIMP":
                    msg = "not a GIMP brush, bad magic number"
                    raise SyntaxError(msg)
                self.info["spacing"] = i32(self.fp.read(4))

            self.info["comment"] = self.fp.read(comment_length)[:-1]

            if color_depth == 1:
                self._mode = "L"
            else:
                self._mode = "RGBA"

            self._size = width, height

            # Image might not be small
            Image._decompression_bomb_check(self.size)

            # Data is an uncompressed block of w * h * bytes/pixel
            self._data_size = width * height * color_depth

        def load(self) -> Image.core.PixelAccess | None:
            if self._im is None:
                assert self.fp is not None
                self.im = Image.core.new(self.mode, self.size)
                self.frombytes(self.fp.read(self._data_size))
            return Image.Image.load(self)

    #
    # registry

    Image.register_open(GbrImageFile.format, GbrImageFile, _accept)
    Image.register_extension(GbrImageFile.format, ".gbr")