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Diffstat (limited to '.venv/lib/python3.12/site-packages/PIL/GifImagePlugin.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/PIL/GifImagePlugin.py | 1197 |
1 files changed, 1197 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/PIL/GifImagePlugin.py b/.venv/lib/python3.12/site-packages/PIL/GifImagePlugin.py new file mode 100644 index 00000000..47022d58 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/PIL/GifImagePlugin.py @@ -0,0 +1,1197 @@ +# +# The Python Imaging Library. +# $Id$ +# +# GIF file handling +# +# History: +# 1995-09-01 fl Created +# 1996-12-14 fl Added interlace support +# 1996-12-30 fl Added animation support +# 1997-01-05 fl Added write support, fixed local colour map bug +# 1997-02-23 fl Make sure to load raster data in getdata() +# 1997-07-05 fl Support external decoder (0.4) +# 1998-07-09 fl Handle all modes when saving (0.5) +# 1998-07-15 fl Renamed offset attribute to avoid name clash +# 2001-04-16 fl Added rewind support (seek to frame 0) (0.6) +# 2001-04-17 fl Added palette optimization (0.7) +# 2002-06-06 fl Added transparency support for save (0.8) +# 2004-02-24 fl Disable interlacing for small images +# +# Copyright (c) 1997-2004 by Secret Labs AB +# Copyright (c) 1995-2004 by Fredrik Lundh +# +# See the README file for information on usage and redistribution. +# +from __future__ import annotations + +import itertools +import math +import os +import subprocess +from enum import IntEnum +from functools import cached_property +from typing import IO, TYPE_CHECKING, Any, Literal, NamedTuple, Union + +from . import ( + Image, + ImageChops, + ImageFile, + ImageMath, + ImageOps, + ImagePalette, + ImageSequence, +) +from ._binary import i16le as i16 +from ._binary import o8 +from ._binary import o16le as o16 + +if TYPE_CHECKING: + from . import _imaging + from ._typing import Buffer + + +class LoadingStrategy(IntEnum): + """.. versionadded:: 9.1.0""" + + RGB_AFTER_FIRST = 0 + RGB_AFTER_DIFFERENT_PALETTE_ONLY = 1 + RGB_ALWAYS = 2 + + +#: .. versionadded:: 9.1.0 +LOADING_STRATEGY = LoadingStrategy.RGB_AFTER_FIRST + +# -------------------------------------------------------------------- +# Identify/read GIF files + + +def _accept(prefix: bytes) -> bool: + return prefix[:6] in [b"GIF87a", b"GIF89a"] + + +## +# Image plugin for GIF images. This plugin supports both GIF87 and +# GIF89 images. + + +class GifImageFile(ImageFile.ImageFile): + format = "GIF" + format_description = "Compuserve GIF" + _close_exclusive_fp_after_loading = False + + global_palette = None + + def data(self) -> bytes | None: + s = self.fp.read(1) + if s and s[0]: + return self.fp.read(s[0]) + return None + + def _is_palette_needed(self, p: bytes) -> bool: + for i in range(0, len(p), 3): + if not (i // 3 == p[i] == p[i + 1] == p[i + 2]): + return True + return False + + def _open(self) -> None: + # Screen + s = self.fp.read(13) + if not _accept(s): + msg = "not a GIF file" + raise SyntaxError(msg) + + self.info["version"] = s[:6] + self._size = i16(s, 6), i16(s, 8) + flags = s[10] + bits = (flags & 7) + 1 + + if flags & 128: + # get global palette + self.info["background"] = s[11] + # check if palette contains colour indices + p = self.fp.read(3 << bits) + if self._is_palette_needed(p): + p = ImagePalette.raw("RGB", p) + self.global_palette = self.palette = p + + self._fp = self.fp # FIXME: hack + self.__rewind = self.fp.tell() + self._n_frames: int | None = None + self._seek(0) # get ready to read first frame + + @property + def n_frames(self) -> int: + if self._n_frames is None: + current = self.tell() + try: + while True: + self._seek(self.tell() + 1, False) + except EOFError: + self._n_frames = self.tell() + 1 + self.seek(current) + return self._n_frames + + @cached_property + def is_animated(self) -> bool: + if self._n_frames is not None: + return self._n_frames != 1 + + current = self.tell() + if current: + return True + + try: + self._seek(1, False) + is_animated = True + except EOFError: + is_animated = False + + self.seek(current) + return is_animated + + def seek(self, frame: int) -> None: + if not self._seek_check(frame): + return + if frame < self.__frame: + self._im = None + self._seek(0) + + last_frame = self.__frame + for f in range(self.__frame + 1, frame + 1): + try: + self._seek(f) + except EOFError as e: + self.seek(last_frame) + msg = "no more images in GIF file" + raise EOFError(msg) from e + + def _seek(self, frame: int, update_image: bool = True) -> None: + if frame == 0: + # rewind + self.__offset = 0 + self.dispose: _imaging.ImagingCore | None = None + self.__frame = -1 + self._fp.seek(self.__rewind) + self.disposal_method = 0 + if "comment" in self.info: + del self.info["comment"] + else: + # ensure that the previous frame was loaded + if self.tile and update_image: + self.load() + + if frame != self.__frame + 1: + msg = f"cannot seek to frame {frame}" + raise ValueError(msg) + + self.fp = self._fp + if self.__offset: + # backup to last frame + self.fp.seek(self.__offset) + while self.data(): + pass + self.__offset = 0 + + s = self.fp.read(1) + if not s or s == b";": + msg = "no more images in GIF file" + raise EOFError(msg) + + palette: ImagePalette.ImagePalette | Literal[False] | None = None + + info: dict[str, Any] = {} + frame_transparency = None + interlace = None + frame_dispose_extent = None + while True: + if not s: + s = self.fp.read(1) + if not s or s == b";": + break + + elif s == b"!": + # + # extensions + # + s = self.fp.read(1) + block = self.data() + if s[0] == 249 and block is not None: + # + # graphic control extension + # + flags = block[0] + if flags & 1: + frame_transparency = block[3] + info["duration"] = i16(block, 1) * 10 + + # disposal method - find the value of bits 4 - 6 + dispose_bits = 0b00011100 & flags + dispose_bits = dispose_bits >> 2 + if dispose_bits: + # only set the dispose if it is not + # unspecified. I'm not sure if this is + # correct, but it seems to prevent the last + # frame from looking odd for some animations + self.disposal_method = dispose_bits + elif s[0] == 254: + # + # comment extension + # + comment = b"" + + # Read this comment block + while block: + comment += block + block = self.data() + + if "comment" in info: + # If multiple comment blocks in frame, separate with \n + info["comment"] += b"\n" + comment + else: + info["comment"] = comment + s = None + continue + elif s[0] == 255 and frame == 0 and block is not None: + # + # application extension + # + info["extension"] = block, self.fp.tell() + if block[:11] == b"NETSCAPE2.0": + block = self.data() + if block and len(block) >= 3 and block[0] == 1: + self.info["loop"] = i16(block, 1) + while self.data(): + pass + + elif s == b",": + # + # local image + # + s = self.fp.read(9) + + # extent + x0, y0 = i16(s, 0), i16(s, 2) + x1, y1 = x0 + i16(s, 4), y0 + i16(s, 6) + if (x1 > self.size[0] or y1 > self.size[1]) and update_image: + self._size = max(x1, self.size[0]), max(y1, self.size[1]) + Image._decompression_bomb_check(self._size) + frame_dispose_extent = x0, y0, x1, y1 + flags = s[8] + + interlace = (flags & 64) != 0 + + if flags & 128: + bits = (flags & 7) + 1 + p = self.fp.read(3 << bits) + if self._is_palette_needed(p): + palette = ImagePalette.raw("RGB", p) + else: + palette = False + + # image data + bits = self.fp.read(1)[0] + self.__offset = self.fp.tell() + break + s = None + + if interlace is None: + msg = "image not found in GIF frame" + raise EOFError(msg) + + self.__frame = frame + if not update_image: + return + + self.tile = [] + + if self.dispose: + self.im.paste(self.dispose, self.dispose_extent) + + self._frame_palette = palette if palette is not None else self.global_palette + self._frame_transparency = frame_transparency + if frame == 0: + if self._frame_palette: + if LOADING_STRATEGY == LoadingStrategy.RGB_ALWAYS: + self._mode = "RGBA" if frame_transparency is not None else "RGB" + else: + self._mode = "P" + else: + self._mode = "L" + + if palette: + self.palette = palette + elif self.global_palette: + from copy import copy + + self.palette = copy(self.global_palette) + else: + self.palette = None + else: + if self.mode == "P": + if ( + LOADING_STRATEGY != LoadingStrategy.RGB_AFTER_DIFFERENT_PALETTE_ONLY + or palette + ): + if "transparency" in self.info: + self.im.putpalettealpha(self.info["transparency"], 0) + self.im = self.im.convert("RGBA", Image.Dither.FLOYDSTEINBERG) + self._mode = "RGBA" + del self.info["transparency"] + else: + self._mode = "RGB" + self.im = self.im.convert("RGB", Image.Dither.FLOYDSTEINBERG) + + def _rgb(color: int) -> tuple[int, int, int]: + if self._frame_palette: + if color * 3 + 3 > len(self._frame_palette.palette): + color = 0 + return tuple(self._frame_palette.palette[color * 3 : color * 3 + 3]) + else: + return (color, color, color) + + self.dispose = None + self.dispose_extent = frame_dispose_extent + if self.dispose_extent and self.disposal_method >= 2: + try: + if self.disposal_method == 2: + # replace with background colour + + # only dispose the extent in this frame + x0, y0, x1, y1 = self.dispose_extent + dispose_size = (x1 - x0, y1 - y0) + + Image._decompression_bomb_check(dispose_size) + + # by convention, attempt to use transparency first + dispose_mode = "P" + color = self.info.get("transparency", frame_transparency) + if color is not None: + if self.mode in ("RGB", "RGBA"): + dispose_mode = "RGBA" + color = _rgb(color) + (0,) + else: + color = self.info.get("background", 0) + if self.mode in ("RGB", "RGBA"): + dispose_mode = "RGB" + color = _rgb(color) + self.dispose = Image.core.fill(dispose_mode, dispose_size, color) + else: + # replace with previous contents + if self._im is not None: + # only dispose the extent in this frame + self.dispose = self._crop(self.im, self.dispose_extent) + elif frame_transparency is not None: + x0, y0, x1, y1 = self.dispose_extent + dispose_size = (x1 - x0, y1 - y0) + + Image._decompression_bomb_check(dispose_size) + dispose_mode = "P" + color = frame_transparency + if self.mode in ("RGB", "RGBA"): + dispose_mode = "RGBA" + color = _rgb(frame_transparency) + (0,) + self.dispose = Image.core.fill( + dispose_mode, dispose_size, color + ) + except AttributeError: + pass + + if interlace is not None: + transparency = -1 + if frame_transparency is not None: + if frame == 0: + if LOADING_STRATEGY != LoadingStrategy.RGB_ALWAYS: + self.info["transparency"] = frame_transparency + elif self.mode not in ("RGB", "RGBA"): + transparency = frame_transparency + self.tile = [ + ImageFile._Tile( + "gif", + (x0, y0, x1, y1), + self.__offset, + (bits, interlace, transparency), + ) + ] + + if info.get("comment"): + self.info["comment"] = info["comment"] + for k in ["duration", "extension"]: + if k in info: + self.info[k] = info[k] + elif k in self.info: + del self.info[k] + + def load_prepare(self) -> None: + temp_mode = "P" if self._frame_palette else "L" + self._prev_im = None + if self.__frame == 0: + if self._frame_transparency is not None: + self.im = Image.core.fill( + temp_mode, self.size, self._frame_transparency + ) + elif self.mode in ("RGB", "RGBA"): + self._prev_im = self.im + if self._frame_palette: + self.im = Image.core.fill("P", self.size, self._frame_transparency or 0) + self.im.putpalette("RGB", *self._frame_palette.getdata()) + else: + self._im = None + if not self._prev_im and self._im is not None and self.size != self.im.size: + expanded_im = Image.core.fill(self.im.mode, self.size) + if self._frame_palette: + expanded_im.putpalette("RGB", *self._frame_palette.getdata()) + expanded_im.paste(self.im, (0, 0) + self.im.size) + + self.im = expanded_im + self._mode = temp_mode + self._frame_palette = None + + super().load_prepare() + + def load_end(self) -> None: + if self.__frame == 0: + if self.mode == "P" and LOADING_STRATEGY == LoadingStrategy.RGB_ALWAYS: + if self._frame_transparency is not None: + self.im.putpalettealpha(self._frame_transparency, 0) + self._mode = "RGBA" + else: + self._mode = "RGB" + self.im = self.im.convert(self.mode, Image.Dither.FLOYDSTEINBERG) + return + if not self._prev_im: + return + if self.size != self._prev_im.size: + if self._frame_transparency is not None: + expanded_im = Image.core.fill("RGBA", self.size) + else: + expanded_im = Image.core.fill("P", self.size) + expanded_im.putpalette("RGB", "RGB", self.im.getpalette()) + expanded_im = expanded_im.convert("RGB") + expanded_im.paste(self._prev_im, (0, 0) + self._prev_im.size) + + self._prev_im = expanded_im + assert self._prev_im is not None + if self._frame_transparency is not None: + self.im.putpalettealpha(self._frame_transparency, 0) + frame_im = self.im.convert("RGBA") + else: + frame_im = self.im.convert("RGB") + + assert self.dispose_extent is not None + frame_im = self._crop(frame_im, self.dispose_extent) + + self.im = self._prev_im + self._mode = self.im.mode + if frame_im.mode == "RGBA": + self.im.paste(frame_im, self.dispose_extent, frame_im) + else: + self.im.paste(frame_im, self.dispose_extent) + + def tell(self) -> int: + return self.__frame + + +# -------------------------------------------------------------------- +# Write GIF files + + +RAWMODE = {"1": "L", "L": "L", "P": "P"} + + +def _normalize_mode(im: Image.Image) -> Image.Image: + """ + Takes an image (or frame), returns an image in a mode that is appropriate + for saving in a Gif. + + It may return the original image, or it may return an image converted to + palette or 'L' mode. + + :param im: Image object + :returns: Image object + """ + if im.mode in RAWMODE: + im.load() + return im + if Image.getmodebase(im.mode) == "RGB": + im = im.convert("P", palette=Image.Palette.ADAPTIVE) + assert im.palette is not None + if im.palette.mode == "RGBA": + for rgba in im.palette.colors: + if rgba[3] == 0: + im.info["transparency"] = im.palette.colors[rgba] + break + return im + return im.convert("L") + + +_Palette = Union[bytes, bytearray, list[int], ImagePalette.ImagePalette] + + +def _normalize_palette( + im: Image.Image, palette: _Palette | None, info: dict[str, Any] +) -> Image.Image: + """ + Normalizes the palette for image. + - Sets the palette to the incoming palette, if provided. + - Ensures that there's a palette for L mode images + - Optimizes the palette if necessary/desired. + + :param im: Image object + :param palette: bytes object containing the source palette, or .... + :param info: encoderinfo + :returns: Image object + """ + source_palette = None + if palette: + # a bytes palette + if isinstance(palette, (bytes, bytearray, list)): + source_palette = bytearray(palette[:768]) + if isinstance(palette, ImagePalette.ImagePalette): + source_palette = bytearray(palette.palette) + + if im.mode == "P": + if not source_palette: + im_palette = im.getpalette(None) + assert im_palette is not None + source_palette = bytearray(im_palette) + else: # L-mode + if not source_palette: + source_palette = bytearray(i // 3 for i in range(768)) + im.palette = ImagePalette.ImagePalette("RGB", palette=source_palette) + assert source_palette is not None + + if palette: + used_palette_colors: list[int | None] = [] + assert im.palette is not None + for i in range(0, len(source_palette), 3): + source_color = tuple(source_palette[i : i + 3]) + index = im.palette.colors.get(source_color) + if index in used_palette_colors: + index = None + used_palette_colors.append(index) + for i, index in enumerate(used_palette_colors): + if index is None: + for j in range(len(used_palette_colors)): + if j not in used_palette_colors: + used_palette_colors[i] = j + break + dest_map: list[int] = [] + for index in used_palette_colors: + assert index is not None + dest_map.append(index) + im = im.remap_palette(dest_map) + else: + optimized_palette_colors = _get_optimize(im, info) + if optimized_palette_colors is not None: + im = im.remap_palette(optimized_palette_colors, source_palette) + if "transparency" in info: + try: + info["transparency"] = optimized_palette_colors.index( + info["transparency"] + ) + except ValueError: + del info["transparency"] + return im + + assert im.palette is not None + im.palette.palette = source_palette + return im + + +def _write_single_frame( + im: Image.Image, + fp: IO[bytes], + palette: _Palette | None, +) -> None: + im_out = _normalize_mode(im) + for k, v in im_out.info.items(): + if isinstance(k, str): + im.encoderinfo.setdefault(k, v) + im_out = _normalize_palette(im_out, palette, im.encoderinfo) + + for s in _get_global_header(im_out, im.encoderinfo): + fp.write(s) + + # local image header + flags = 0 + if get_interlace(im): + flags = flags | 64 + _write_local_header(fp, im, (0, 0), flags) + + im_out.encoderconfig = (8, get_interlace(im)) + ImageFile._save( + im_out, fp, [ImageFile._Tile("gif", (0, 0) + im.size, 0, RAWMODE[im_out.mode])] + ) + + fp.write(b"\0") # end of image data + + +def _getbbox( + base_im: Image.Image, im_frame: Image.Image +) -> tuple[Image.Image, tuple[int, int, int, int] | None]: + palette_bytes = [ + bytes(im.palette.palette) if im.palette else b"" for im in (base_im, im_frame) + ] + if palette_bytes[0] != palette_bytes[1]: + im_frame = im_frame.convert("RGBA") + base_im = base_im.convert("RGBA") + delta = ImageChops.subtract_modulo(im_frame, base_im) + return delta, delta.getbbox(alpha_only=False) + + +class _Frame(NamedTuple): + im: Image.Image + bbox: tuple[int, int, int, int] | None + encoderinfo: dict[str, Any] + + +def _write_multiple_frames( + im: Image.Image, fp: IO[bytes], palette: _Palette | None +) -> bool: + duration = im.encoderinfo.get("duration") + disposal = im.encoderinfo.get("disposal", im.info.get("disposal")) + + im_frames: list[_Frame] = [] + previous_im: Image.Image | None = None + frame_count = 0 + background_im = None + for imSequence in itertools.chain([im], im.encoderinfo.get("append_images", [])): + for im_frame in ImageSequence.Iterator(imSequence): + # a copy is required here since seek can still mutate the image + im_frame = _normalize_mode(im_frame.copy()) + if frame_count == 0: + for k, v in im_frame.info.items(): + if k == "transparency": + continue + if isinstance(k, str): + im.encoderinfo.setdefault(k, v) + + encoderinfo = im.encoderinfo.copy() + if "transparency" in im_frame.info: + encoderinfo.setdefault("transparency", im_frame.info["transparency"]) + im_frame = _normalize_palette(im_frame, palette, encoderinfo) + if isinstance(duration, (list, tuple)): + encoderinfo["duration"] = duration[frame_count] + elif duration is None and "duration" in im_frame.info: + encoderinfo["duration"] = im_frame.info["duration"] + if isinstance(disposal, (list, tuple)): + encoderinfo["disposal"] = disposal[frame_count] + frame_count += 1 + + diff_frame = None + if im_frames and previous_im: + # delta frame + delta, bbox = _getbbox(previous_im, im_frame) + if not bbox: + # This frame is identical to the previous frame + if encoderinfo.get("duration"): + im_frames[-1].encoderinfo["duration"] += encoderinfo["duration"] + continue + if im_frames[-1].encoderinfo.get("disposal") == 2: + if background_im is None: + color = im.encoderinfo.get( + "transparency", im.info.get("transparency", (0, 0, 0)) + ) + background = _get_background(im_frame, color) + background_im = Image.new("P", im_frame.size, background) + first_palette = im_frames[0].im.palette + assert first_palette is not None + background_im.putpalette(first_palette, first_palette.mode) + bbox = _getbbox(background_im, im_frame)[1] + elif encoderinfo.get("optimize") and im_frame.mode != "1": + if "transparency" not in encoderinfo: + assert im_frame.palette is not None + try: + encoderinfo["transparency"] = ( + im_frame.palette._new_color_index(im_frame) + ) + except ValueError: + pass + if "transparency" in encoderinfo: + # When the delta is zero, fill the image with transparency + diff_frame = im_frame.copy() + fill = Image.new("P", delta.size, encoderinfo["transparency"]) + if delta.mode == "RGBA": + r, g, b, a = delta.split() + mask = ImageMath.lambda_eval( + lambda args: args["convert"]( + args["max"]( + args["max"]( + args["max"](args["r"], args["g"]), args["b"] + ), + args["a"], + ) + * 255, + "1", + ), + r=r, + g=g, + b=b, + a=a, + ) + else: + if delta.mode == "P": + # Convert to L without considering palette + delta_l = Image.new("L", delta.size) + delta_l.putdata(delta.getdata()) + delta = delta_l + mask = ImageMath.lambda_eval( + lambda args: args["convert"](args["im"] * 255, "1"), + im=delta, + ) + diff_frame.paste(fill, mask=ImageOps.invert(mask)) + else: + bbox = None + previous_im = im_frame + im_frames.append(_Frame(diff_frame or im_frame, bbox, encoderinfo)) + + if len(im_frames) == 1: + if "duration" in im.encoderinfo: + # Since multiple frames will not be written, use the combined duration + im.encoderinfo["duration"] = im_frames[0].encoderinfo["duration"] + return False + + for frame_data in im_frames: + im_frame = frame_data.im + if not frame_data.bbox: + # global header + for s in _get_global_header(im_frame, frame_data.encoderinfo): + fp.write(s) + offset = (0, 0) + else: + # compress difference + if not palette: + frame_data.encoderinfo["include_color_table"] = True + + im_frame = im_frame.crop(frame_data.bbox) + offset = frame_data.bbox[:2] + _write_frame_data(fp, im_frame, offset, frame_data.encoderinfo) + return True + + +def _save_all(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None: + _save(im, fp, filename, save_all=True) + + +def _save( + im: Image.Image, fp: IO[bytes], filename: str | bytes, save_all: bool = False +) -> None: + # header + if "palette" in im.encoderinfo or "palette" in im.info: + palette = im.encoderinfo.get("palette", im.info.get("palette")) + else: + palette = None + im.encoderinfo.setdefault("optimize", True) + + if not save_all or not _write_multiple_frames(im, fp, palette): + _write_single_frame(im, fp, palette) + + fp.write(b";") # end of file + + if hasattr(fp, "flush"): + fp.flush() + + +def get_interlace(im: Image.Image) -> int: + interlace = im.encoderinfo.get("interlace", 1) + + # workaround for @PIL153 + if min(im.size) < 16: + interlace = 0 + + return interlace + + +def _write_local_header( + fp: IO[bytes], im: Image.Image, offset: tuple[int, int], flags: int +) -> None: + try: + transparency = im.encoderinfo["transparency"] + except KeyError: + transparency = None + + if "duration" in im.encoderinfo: + duration = int(im.encoderinfo["duration"] / 10) + else: + duration = 0 + + disposal = int(im.encoderinfo.get("disposal", 0)) + + if transparency is not None or duration != 0 or disposal: + packed_flag = 1 if transparency is not None else 0 + packed_flag |= disposal << 2 + + fp.write( + b"!" + + o8(249) # extension intro + + o8(4) # length + + o8(packed_flag) # packed fields + + o16(duration) # duration + + o8(transparency or 0) # transparency index + + o8(0) + ) + + include_color_table = im.encoderinfo.get("include_color_table") + if include_color_table: + palette_bytes = _get_palette_bytes(im) + color_table_size = _get_color_table_size(palette_bytes) + if color_table_size: + flags = flags | 128 # local color table flag + flags = flags | color_table_size + + fp.write( + b"," + + o16(offset[0]) # offset + + o16(offset[1]) + + o16(im.size[0]) # size + + o16(im.size[1]) + + o8(flags) # flags + ) + if include_color_table and color_table_size: + fp.write(_get_header_palette(palette_bytes)) + fp.write(o8(8)) # bits + + +def _save_netpbm(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None: + # Unused by default. + # To use, uncomment the register_save call at the end of the file. + # + # If you need real GIF compression and/or RGB quantization, you + # can use the external NETPBM/PBMPLUS utilities. See comments + # below for information on how to enable this. + tempfile = im._dump() + + try: + with open(filename, "wb") as f: + if im.mode != "RGB": + subprocess.check_call( + ["ppmtogif", tempfile], stdout=f, stderr=subprocess.DEVNULL + ) + else: + # Pipe ppmquant output into ppmtogif + # "ppmquant 256 %s | ppmtogif > %s" % (tempfile, filename) + quant_cmd = ["ppmquant", "256", tempfile] + togif_cmd = ["ppmtogif"] + quant_proc = subprocess.Popen( + quant_cmd, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL + ) + togif_proc = subprocess.Popen( + togif_cmd, + stdin=quant_proc.stdout, + stdout=f, + stderr=subprocess.DEVNULL, + ) + + # Allow ppmquant to receive SIGPIPE if ppmtogif exits + assert quant_proc.stdout is not None + quant_proc.stdout.close() + + retcode = quant_proc.wait() + if retcode: + raise subprocess.CalledProcessError(retcode, quant_cmd) + + retcode = togif_proc.wait() + if retcode: + raise subprocess.CalledProcessError(retcode, togif_cmd) + finally: + try: + os.unlink(tempfile) + except OSError: + pass + + +# Force optimization so that we can test performance against +# cases where it took lots of memory and time previously. +_FORCE_OPTIMIZE = False + + +def _get_optimize(im: Image.Image, info: dict[str, Any]) -> list[int] | None: + """ + Palette optimization is a potentially expensive operation. + + This function determines if the palette should be optimized using + some heuristics, then returns the list of palette entries in use. + + :param im: Image object + :param info: encoderinfo + :returns: list of indexes of palette entries in use, or None + """ + if im.mode in ("P", "L") and info and info.get("optimize"): + # Potentially expensive operation. + + # The palette saves 3 bytes per color not used, but palette + # lengths are restricted to 3*(2**N) bytes. Max saving would + # be 768 -> 6 bytes if we went all the way down to 2 colors. + # * If we're over 128 colors, we can't save any space. + # * If there aren't any holes, it's not worth collapsing. + # * If we have a 'large' image, the palette is in the noise. + + # create the new palette if not every color is used + optimise = _FORCE_OPTIMIZE or im.mode == "L" + if optimise or im.width * im.height < 512 * 512: + # check which colors are used + used_palette_colors = [] + for i, count in enumerate(im.histogram()): + if count: + used_palette_colors.append(i) + + if optimise or max(used_palette_colors) >= len(used_palette_colors): + return used_palette_colors + + assert im.palette is not None + num_palette_colors = len(im.palette.palette) // Image.getmodebands( + im.palette.mode + ) + current_palette_size = 1 << (num_palette_colors - 1).bit_length() + if ( + # check that the palette would become smaller when saved + len(used_palette_colors) <= current_palette_size // 2 + # check that the palette is not already the smallest possible size + and current_palette_size > 2 + ): + return used_palette_colors + return None + + +def _get_color_table_size(palette_bytes: bytes) -> int: + # calculate the palette size for the header + if not palette_bytes: + return 0 + elif len(palette_bytes) < 9: + return 1 + else: + return math.ceil(math.log(len(palette_bytes) // 3, 2)) - 1 + + +def _get_header_palette(palette_bytes: bytes) -> bytes: + """ + Returns the palette, null padded to the next power of 2 (*3) bytes + suitable for direct inclusion in the GIF header + + :param palette_bytes: Unpadded palette bytes, in RGBRGB form + :returns: Null padded palette + """ + color_table_size = _get_color_table_size(palette_bytes) + + # add the missing amount of bytes + # the palette has to be 2<<n in size + actual_target_size_diff = (2 << color_table_size) - len(palette_bytes) // 3 + if actual_target_size_diff > 0: + palette_bytes += o8(0) * 3 * actual_target_size_diff + return palette_bytes + + +def _get_palette_bytes(im: Image.Image) -> bytes: + """ + Gets the palette for inclusion in the gif header + + :param im: Image object + :returns: Bytes, len<=768 suitable for inclusion in gif header + """ + if not im.palette: + return b"" + + palette = bytes(im.palette.palette) + if im.palette.mode == "RGBA": + palette = b"".join(palette[i * 4 : i * 4 + 3] for i in range(len(palette) // 3)) + return palette + + +def _get_background( + im: Image.Image, + info_background: int | tuple[int, int, int] | tuple[int, int, int, int] | None, +) -> int: + background = 0 + if info_background: + if isinstance(info_background, tuple): + # WebPImagePlugin stores an RGBA value in info["background"] + # So it must be converted to the same format as GifImagePlugin's + # info["background"] - a global color table index + assert im.palette is not None + try: + background = im.palette.getcolor(info_background, im) + except ValueError as e: + if str(e) not in ( + # If all 256 colors are in use, + # then there is no need for the background color + "cannot allocate more than 256 colors", + # Ignore non-opaque WebP background + "cannot add non-opaque RGBA color to RGB palette", + ): + raise + else: + background = info_background + return background + + +def _get_global_header(im: Image.Image, info: dict[str, Any]) -> list[bytes]: + """Return a list of strings representing a GIF header""" + + # Header Block + # https://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp + + version = b"87a" + if im.info.get("version") == b"89a" or ( + info + and ( + "transparency" in info + or info.get("loop") is not None + or info.get("duration") + or info.get("comment") + ) + ): + version = b"89a" + + background = _get_background(im, info.get("background")) + + palette_bytes = _get_palette_bytes(im) + color_table_size = _get_color_table_size(palette_bytes) + + header = [ + b"GIF" # signature + + version # version + + o16(im.size[0]) # canvas width + + o16(im.size[1]), # canvas height + # Logical Screen Descriptor + # size of global color table + global color table flag + o8(color_table_size + 128), # packed fields + # background + reserved/aspect + o8(background) + o8(0), + # Global Color Table + _get_header_palette(palette_bytes), + ] + if info.get("loop") is not None: + header.append( + b"!" + + o8(255) # extension intro + + o8(11) + + b"NETSCAPE2.0" + + o8(3) + + o8(1) + + o16(info["loop"]) # number of loops + + o8(0) + ) + if info.get("comment"): + comment_block = b"!" + o8(254) # extension intro + + comment = info["comment"] + if isinstance(comment, str): + comment = comment.encode() + for i in range(0, len(comment), 255): + subblock = comment[i : i + 255] + comment_block += o8(len(subblock)) + subblock + + comment_block += o8(0) + header.append(comment_block) + return header + + +def _write_frame_data( + fp: IO[bytes], + im_frame: Image.Image, + offset: tuple[int, int], + params: dict[str, Any], +) -> None: + try: + im_frame.encoderinfo = params + + # local image header + _write_local_header(fp, im_frame, offset, 0) + + ImageFile._save( + im_frame, + fp, + [ImageFile._Tile("gif", (0, 0) + im_frame.size, 0, RAWMODE[im_frame.mode])], + ) + + fp.write(b"\0") # end of image data + finally: + del im_frame.encoderinfo + + +# -------------------------------------------------------------------- +# Legacy GIF utilities + + +def getheader( + im: Image.Image, palette: _Palette | None = None, info: dict[str, Any] | None = None +) -> tuple[list[bytes], list[int] | None]: + """ + Legacy Method to get Gif data from image. + + Warning:: May modify image data. + + :param im: Image object + :param palette: bytes object containing the source palette, or .... + :param info: encoderinfo + :returns: tuple of(list of header items, optimized palette) + + """ + if info is None: + info = {} + + used_palette_colors = _get_optimize(im, info) + + if "background" not in info and "background" in im.info: + info["background"] = im.info["background"] + + im_mod = _normalize_palette(im, palette, info) + im.palette = im_mod.palette + im.im = im_mod.im + header = _get_global_header(im, info) + + return header, used_palette_colors + + +def getdata( + im: Image.Image, offset: tuple[int, int] = (0, 0), **params: Any +) -> list[bytes]: + """ + Legacy Method + + Return a list of strings representing this image. + The first string is a local image header, the rest contains + encoded image data. + + To specify duration, add the time in milliseconds, + e.g. ``getdata(im_frame, duration=1000)`` + + :param im: Image object + :param offset: Tuple of (x, y) pixels. Defaults to (0, 0) + :param \\**params: e.g. duration or other encoder info parameters + :returns: List of bytes containing GIF encoded frame data + + """ + from io import BytesIO + + class Collector(BytesIO): + data = [] + + def write(self, data: Buffer) -> int: + self.data.append(data) + return len(data) + + im.load() # make sure raster data is available + + fp = Collector() + + _write_frame_data(fp, im, offset, params) + + return fp.data + + +# -------------------------------------------------------------------- +# Registry + +Image.register_open(GifImageFile.format, GifImageFile, _accept) +Image.register_save(GifImageFile.format, _save) +Image.register_save_all(GifImageFile.format, _save_all) +Image.register_extension(GifImageFile.format, ".gif") +Image.register_mime(GifImageFile.format, "image/gif") + +# +# Uncomment the following line if you wish to use NETPBM/PBMPLUS +# instead of the built-in "uncompressed" GIF encoder + +# Image.register_save(GifImageFile.format, _save_netpbm) |