Hide navigation sidebar
Hide table of contents sidebar
Skip to content
Back to top
Toggle table of contents sidebar

# Source code for PIL.SunImagePlugin

    #
    # The Python Imaging Library.
    # $Id$
    #
    # Sun image file handling
    #
    # History:
    # 1995-09-10 fl   Created
    # 1996-05-28 fl   Fixed 32-bit alignment
    # 1998-12-29 fl   Import ImagePalette module
    # 2001-12-18 fl   Fixed palette loading (from Jean-Claude Rimbault)
    #
    # Copyright (c) 1997-2001 by Secret Labs AB
    # Copyright (c) 1995-1996 by Fredrik Lundh
    #
    # See the README file for information on usage and redistribution.
    #
    from __future__ import annotations

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

    def _accept(prefix: bytes) -> bool:
        return len(prefix) >= 4 and i32(prefix) == 0x59A66A95

    ##
    # Image plugin for Sun raster files.

    class SunImageFile(ImageFile.ImageFile):
        format = "SUN"
        format_description = "Sun Raster File"

        def _open(self) -> None:
            # The Sun Raster file header is 32 bytes in length
            # and has the following format:

            #     typedef struct _SunRaster
            #     {
            #         DWORD MagicNumber;      /* Magic (identification) number */
            #         DWORD Width;            /* Width of image in pixels */
            #         DWORD Height;           /* Height of image in pixels */
            #         DWORD Depth;            /* Number of bits per pixel */
            #         DWORD Length;           /* Size of image data in bytes */
            #         DWORD Type;             /* Type of raster file */
            #         DWORD ColorMapType;     /* Type of color map */
            #         DWORD ColorMapLength;   /* Size of the color map in bytes */
            #     } SUNRASTER;

            assert self.fp is not None

            # HEAD
            s = self.fp.read(32)
            if not _accept(s):
                msg = "not an SUN raster file"
                raise SyntaxError(msg)

            offset = 32

            self._size = i32(s, 4), i32(s, 8)

            depth = i32(s, 12)
            # data_length = i32(s, 16)   # unreliable, ignore.
            file_type = i32(s, 20)
            palette_type = i32(s, 24)  # 0: None, 1: RGB, 2: Raw/arbitrary
            palette_length = i32(s, 28)

            if depth == 1:
                self._mode, rawmode = "1", "1;I"
            elif depth == 4:
                self._mode, rawmode = "L", "L;4"
            elif depth == 8:
                self._mode = rawmode = "L"
            elif depth == 24:
                if file_type == 3:
                    self._mode, rawmode = "RGB", "RGB"
                else:
                    self._mode, rawmode = "RGB", "BGR"
            elif depth == 32:
                if file_type == 3:
                    self._mode, rawmode = "RGB", "RGBX"
                else:
                    self._mode, rawmode = "RGB", "BGRX"
            else:
                msg = "Unsupported Mode/Bit Depth"
                raise SyntaxError(msg)

            if palette_length:
                if palette_length > 1024:
                    msg = "Unsupported Color Palette Length"
                    raise SyntaxError(msg)

                if palette_type != 1:
                    msg = "Unsupported Palette Type"
                    raise SyntaxError(msg)

                offset = offset + palette_length
                self.palette = ImagePalette.raw("RGB;L", self.fp.read(palette_length))
                if self.mode == "L":
                    self._mode = "P"
                    rawmode = rawmode.replace("L", "P")

            # 16 bit boundaries on stride
            stride = ((self.size[0] * depth + 15) // 16) * 2

            # file type: Type is the version (or flavor) of the bitmap
            # file. The following values are typically found in the Type
            # field:
            # 0000h Old
            # 0001h Standard
            # 0002h Byte-encoded
            # 0003h RGB format
            # 0004h TIFF format
            # 0005h IFF format
            # FFFFh Experimental

            # Old and standard are the same, except for the length tag.
            # byte-encoded is run-length-encoded
            # RGB looks similar to standard, but RGB byte order
            # TIFF and IFF mean that they were converted from T/IFF
            # Experimental means that it's something else.
            # (https://www.fileformat.info/format/sunraster/egff.htm)

            if file_type in (0, 1, 3, 4, 5):
                self.tile = [
                    ImageFile._Tile("raw", (0, 0) + self.size, offset, (rawmode, stride))
                ]
            elif file_type == 2:
                self.tile = [
                    ImageFile._Tile("sun_rle", (0, 0) + self.size, offset, rawmode)
                ]
            else:
                msg = "Unsupported Sun Raster file type"
                raise SyntaxError(msg)

    #
    # registry

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

    Image.register_extension(SunImageFile.format, ".ras")