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Diffstat (limited to 'venv/lib/python3.9/site-packages/PIL/ImagePalette.py')
| -rw-r--r-- | venv/lib/python3.9/site-packages/PIL/ImagePalette.py | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/venv/lib/python3.9/site-packages/PIL/ImagePalette.py b/venv/lib/python3.9/site-packages/PIL/ImagePalette.py new file mode 100644 index 00000000..e455c045 --- /dev/null +++ b/venv/lib/python3.9/site-packages/PIL/ImagePalette.py @@ -0,0 +1,272 @@ +# +# The Python Imaging Library. +# $Id$ +# +# image palette object +# +# History: +# 1996-03-11 fl Rewritten. +# 1997-01-03 fl Up and running. +# 1997-08-23 fl Added load hack +# 2001-04-16 fl Fixed randint shadow bug in random() +# +# Copyright (c) 1997-2001 by Secret Labs AB +# Copyright (c) 1996-1997 by Fredrik Lundh +# +# See the README file for information on usage and redistribution. +# + +import array + +from . import GimpGradientFile, GimpPaletteFile, ImageColor, PaletteFile +from ._deprecate import deprecate + + +class ImagePalette: + """ + Color palette for palette mapped images + + :param mode: The mode to use for the palette. See: + :ref:`concept-modes`. Defaults to "RGB" + :param palette: An optional palette. If given, it must be a bytearray, + an array or a list of ints between 0-255. The list must consist of + all channels for one color followed by the next color (e.g. RGBRGBRGB). + Defaults to an empty palette. + """ + + def __init__(self, mode="RGB", palette=None, size=0): + self.mode = mode + self.rawmode = None # if set, palette contains raw data + self.palette = palette or bytearray() + self.dirty = None + if size != 0: + deprecate("The size parameter", 10, None) + if size != len(self.palette): + msg = "wrong palette size" + raise ValueError(msg) + + @property + def palette(self): + return self._palette + + @palette.setter + def palette(self, palette): + self._colors = None + self._palette = palette + + @property + def colors(self): + if self._colors is None: + mode_len = len(self.mode) + self._colors = {} + for i in range(0, len(self.palette), mode_len): + color = tuple(self.palette[i : i + mode_len]) + if color in self._colors: + continue + self._colors[color] = i // mode_len + return self._colors + + @colors.setter + def colors(self, colors): + self._colors = colors + + def copy(self): + new = ImagePalette() + + new.mode = self.mode + new.rawmode = self.rawmode + if self.palette is not None: + new.palette = self.palette[:] + new.dirty = self.dirty + + return new + + def getdata(self): + """ + Get palette contents in format suitable for the low-level + ``im.putpalette`` primitive. + + .. warning:: This method is experimental. + """ + if self.rawmode: + return self.rawmode, self.palette + return self.mode, self.tobytes() + + def tobytes(self): + """Convert palette to bytes. + + .. warning:: This method is experimental. + """ + if self.rawmode: + msg = "palette contains raw palette data" + raise ValueError(msg) + if isinstance(self.palette, bytes): + return self.palette + arr = array.array("B", self.palette) + return arr.tobytes() + + # Declare tostring as an alias for tobytes + tostring = tobytes + + def getcolor(self, color, image=None): + """Given an rgb tuple, allocate palette entry. + + .. warning:: This method is experimental. + """ + if self.rawmode: + msg = "palette contains raw palette data" + raise ValueError(msg) + if isinstance(color, tuple): + if self.mode == "RGB": + if len(color) == 4: + if color[3] != 255: + msg = "cannot add non-opaque RGBA color to RGB palette" + raise ValueError(msg) + color = color[:3] + elif self.mode == "RGBA": + if len(color) == 3: + color += (255,) + try: + return self.colors[color] + except KeyError as e: + # allocate new color slot + if not isinstance(self.palette, bytearray): + self._palette = bytearray(self.palette) + index = len(self.palette) // 3 + special_colors = () + if image: + special_colors = ( + image.info.get("background"), + image.info.get("transparency"), + ) + while index in special_colors: + index += 1 + if index >= 256: + if image: + # Search for an unused index + for i, count in reversed(list(enumerate(image.histogram()))): + if count == 0 and i not in special_colors: + index = i + break + if index >= 256: + msg = "cannot allocate more than 256 colors" + raise ValueError(msg) from e + self.colors[color] = index + if index * 3 < len(self.palette): + self._palette = ( + self.palette[: index * 3] + + bytes(color) + + self.palette[index * 3 + 3 :] + ) + else: + self._palette += bytes(color) + self.dirty = 1 + return index + else: + msg = f"unknown color specifier: {repr(color)}" + raise ValueError(msg) + + def save(self, fp): + """Save palette to text file. + + .. warning:: This method is experimental. + """ + if self.rawmode: + msg = "palette contains raw palette data" + raise ValueError(msg) + if isinstance(fp, str): + fp = open(fp, "w") + fp.write("# Palette\n") + fp.write(f"# Mode: {self.mode}\n") + for i in range(256): + fp.write(f"{i}") + for j in range(i * len(self.mode), (i + 1) * len(self.mode)): + try: + fp.write(f" {self.palette[j]}") + except IndexError: + fp.write(" 0") + fp.write("\n") + fp.close() + + +# -------------------------------------------------------------------- +# Internal + + +def raw(rawmode, data): + palette = ImagePalette() + palette.rawmode = rawmode + palette.palette = data + palette.dirty = 1 + return palette + + +# -------------------------------------------------------------------- +# Factories + + +def make_linear_lut(black, white): + lut = [] + if black == 0: + for i in range(256): + lut.append(white * i // 255) + else: + raise NotImplementedError # FIXME + return lut + + +def make_gamma_lut(exp): + lut = [] + for i in range(256): + lut.append(int(((i / 255.0) ** exp) * 255.0 + 0.5)) + return lut + + +def negative(mode="RGB"): + palette = list(range(256 * len(mode))) + palette.reverse() + return ImagePalette(mode, [i // len(mode) for i in palette]) + + +def random(mode="RGB"): + from random import randint + + palette = [] + for i in range(256 * len(mode)): + palette.append(randint(0, 255)) + return ImagePalette(mode, palette) + + +def sepia(white="#fff0c0"): + bands = [make_linear_lut(0, band) for band in ImageColor.getrgb(white)] + return ImagePalette("RGB", [bands[i % 3][i // 3] for i in range(256 * 3)]) + + +def wedge(mode="RGB"): + palette = list(range(256 * len(mode))) + return ImagePalette(mode, [i // len(mode) for i in palette]) + + +def load(filename): + # FIXME: supports GIMP gradients only + + with open(filename, "rb") as fp: + for paletteHandler in [ + GimpPaletteFile.GimpPaletteFile, + GimpGradientFile.GimpGradientFile, + PaletteFile.PaletteFile, + ]: + try: + fp.seek(0) + lut = paletteHandler(fp).getpalette() + if lut: + break + except (SyntaxError, ValueError): + # import traceback + # traceback.print_exc() + pass + else: + msg = "cannot load palette" + raise OSError(msg) + + return lut # data, rawmode |