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Diffstat (limited to '.venv/lib/python3.12/site-packages/PIL/SgiImagePlugin.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/PIL/SgiImagePlugin.py | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/PIL/SgiImagePlugin.py b/.venv/lib/python3.12/site-packages/PIL/SgiImagePlugin.py new file mode 100644 index 00000000..44254b7a --- /dev/null +++ b/.venv/lib/python3.12/site-packages/PIL/SgiImagePlugin.py @@ -0,0 +1,247 @@ +# +# The Python Imaging Library. +# $Id$ +# +# SGI image file handling +# +# See "The SGI Image File Format (Draft version 0.97)", Paul Haeberli. +# <ftp://ftp.sgi.com/graphics/SGIIMAGESPEC> +# +# +# History: +# 2017-22-07 mb Add RLE decompression +# 2016-16-10 mb Add save method without compression +# 1995-09-10 fl Created +# +# Copyright (c) 2016 by Mickael Bonfill. +# Copyright (c) 2008 by Karsten Hiddemann. +# Copyright (c) 1997 by Secret Labs AB. +# Copyright (c) 1995 by Fredrik Lundh. +# +# See the README file for information on usage and redistribution. +# +from __future__ import annotations + +import os +import struct +from typing import IO + +from . import Image, ImageFile +from ._binary import i16be as i16 +from ._binary import o8 + + +def _accept(prefix: bytes) -> bool: + return len(prefix) >= 2 and i16(prefix) == 474 + + +MODES = { + (1, 1, 1): "L", + (1, 2, 1): "L", + (2, 1, 1): "L;16B", + (2, 2, 1): "L;16B", + (1, 3, 3): "RGB", + (2, 3, 3): "RGB;16B", + (1, 3, 4): "RGBA", + (2, 3, 4): "RGBA;16B", +} + + +## +# Image plugin for SGI images. +class SgiImageFile(ImageFile.ImageFile): + format = "SGI" + format_description = "SGI Image File Format" + + def _open(self) -> None: + # HEAD + assert self.fp is not None + + headlen = 512 + s = self.fp.read(headlen) + + if not _accept(s): + msg = "Not an SGI image file" + raise ValueError(msg) + + # compression : verbatim or RLE + compression = s[2] + + # bpc : 1 or 2 bytes (8bits or 16bits) + bpc = s[3] + + # dimension : 1, 2 or 3 (depending on xsize, ysize and zsize) + dimension = i16(s, 4) + + # xsize : width + xsize = i16(s, 6) + + # ysize : height + ysize = i16(s, 8) + + # zsize : channels count + zsize = i16(s, 10) + + # layout + layout = bpc, dimension, zsize + + # determine mode from bits/zsize + rawmode = "" + try: + rawmode = MODES[layout] + except KeyError: + pass + + if rawmode == "": + msg = "Unsupported SGI image mode" + raise ValueError(msg) + + self._size = xsize, ysize + self._mode = rawmode.split(";")[0] + if self.mode == "RGB": + self.custom_mimetype = "image/rgb" + + # orientation -1 : scanlines begins at the bottom-left corner + orientation = -1 + + # decoder info + if compression == 0: + pagesize = xsize * ysize * bpc + if bpc == 2: + self.tile = [ + ImageFile._Tile( + "SGI16", + (0, 0) + self.size, + headlen, + (self.mode, 0, orientation), + ) + ] + else: + self.tile = [] + offset = headlen + for layer in self.mode: + self.tile.append( + ImageFile._Tile( + "raw", (0, 0) + self.size, offset, (layer, 0, orientation) + ) + ) + offset += pagesize + elif compression == 1: + self.tile = [ + ImageFile._Tile( + "sgi_rle", (0, 0) + self.size, headlen, (rawmode, orientation, bpc) + ) + ] + + +def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None: + if im.mode not in {"RGB", "RGBA", "L"}: + msg = "Unsupported SGI image mode" + raise ValueError(msg) + + # Get the keyword arguments + info = im.encoderinfo + + # Byte-per-pixel precision, 1 = 8bits per pixel + bpc = info.get("bpc", 1) + + if bpc not in (1, 2): + msg = "Unsupported number of bytes per pixel" + raise ValueError(msg) + + # Flip the image, since the origin of SGI file is the bottom-left corner + orientation = -1 + # Define the file as SGI File Format + magic_number = 474 + # Run-Length Encoding Compression - Unsupported at this time + rle = 0 + + # Number of dimensions (x,y,z) + dim = 3 + # X Dimension = width / Y Dimension = height + x, y = im.size + if im.mode == "L" and y == 1: + dim = 1 + elif im.mode == "L": + dim = 2 + # Z Dimension: Number of channels + z = len(im.mode) + + if dim in {1, 2}: + z = 1 + + # assert we've got the right number of bands. + if len(im.getbands()) != z: + msg = f"incorrect number of bands in SGI write: {z} vs {len(im.getbands())}" + raise ValueError(msg) + + # Minimum Byte value + pinmin = 0 + # Maximum Byte value (255 = 8bits per pixel) + pinmax = 255 + # Image name (79 characters max, truncated below in write) + img_name = os.path.splitext(os.path.basename(filename))[0] + if isinstance(img_name, str): + img_name = img_name.encode("ascii", "ignore") + # Standard representation of pixel in the file + colormap = 0 + fp.write(struct.pack(">h", magic_number)) + fp.write(o8(rle)) + fp.write(o8(bpc)) + fp.write(struct.pack(">H", dim)) + fp.write(struct.pack(">H", x)) + fp.write(struct.pack(">H", y)) + fp.write(struct.pack(">H", z)) + fp.write(struct.pack(">l", pinmin)) + fp.write(struct.pack(">l", pinmax)) + fp.write(struct.pack("4s", b"")) # dummy + fp.write(struct.pack("79s", img_name)) # truncates to 79 chars + fp.write(struct.pack("s", b"")) # force null byte after img_name + fp.write(struct.pack(">l", colormap)) + fp.write(struct.pack("404s", b"")) # dummy + + rawmode = "L" + if bpc == 2: + rawmode = "L;16B" + + for channel in im.split(): + fp.write(channel.tobytes("raw", rawmode, 0, orientation)) + + if hasattr(fp, "flush"): + fp.flush() + + +class SGI16Decoder(ImageFile.PyDecoder): + _pulls_fd = True + + def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]: + assert self.fd is not None + assert self.im is not None + + rawmode, stride, orientation = self.args + pagesize = self.state.xsize * self.state.ysize + zsize = len(self.mode) + self.fd.seek(512) + + for band in range(zsize): + channel = Image.new("L", (self.state.xsize, self.state.ysize)) + channel.frombytes( + self.fd.read(2 * pagesize), "raw", "L;16B", stride, orientation + ) + self.im.putband(channel.im, band) + + return -1, 0 + + +# +# registry + + +Image.register_decoder("SGI16", SGI16Decoder) +Image.register_open(SgiImageFile.format, SgiImageFile, _accept) +Image.register_save(SgiImageFile.format, _save) +Image.register_mime(SgiImageFile.format, "image/sgi") + +Image.register_extensions(SgiImageFile.format, [".bw", ".rgb", ".rgba", ".sgi"]) + +# End of file |