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Editing: IcoImagePlugin.py
# # The Python Imaging Library. # $Id$ # # Windows Icon support for PIL # # History: # 96-05-27 fl Created # # Copyright (c) Secret Labs AB 1997. # Copyright (c) Fredrik Lundh 1996. # # See the README file for information on usage and redistribution. # # This plugin is a refactored version of Win32IconImagePlugin by Bryan Davis # <casadebender@gmail.com>. # https://code.google.com/archive/p/casadebender/wikis/Win32IconImagePlugin.wiki # # Icon format references: # * https://en.wikipedia.org/wiki/ICO_(file_format) # * https://msdn.microsoft.com/en-us/library/ms997538.aspx import warnings from io import BytesIO from math import ceil, log from . import BmpImagePlugin, Image, ImageFile, PngImagePlugin from ._binary import i16le as i16 from ._binary import i32le as i32 from ._binary import o8 from ._binary import o16le as o16 from ._binary import o32le as o32 # # -------------------------------------------------------------------- _MAGIC = b"\0\0\1\0" def _save(im, fp, filename): fp.write(_MAGIC) # (2+2) bmp = im.encoderinfo.get("bitmap_format") == "bmp" sizes = im.encoderinfo.get( "sizes", [(16, 16), (24, 24), (32, 32), (48, 48), (64, 64), (128, 128), (256, 256)], ) frames = [] provided_ims = [im] + im.encoderinfo.get("append_images", []) width, height = im.size for size in sorted(set(sizes)): if size[0] > width or size[1] > height or size[0] > 256 or size[1] > 256: continue for provided_im in provided_ims: if provided_im.size != size: continue frames.append(provided_im) if bmp: bits = BmpImagePlugin.SAVE[provided_im.mode][1] bits_used = [bits] for other_im in provided_ims: if other_im.size != size: continue bits = BmpImagePlugin.SAVE[other_im.mode][1] if bits not in bits_used: # Another image has been supplied for this size # with a different bit depth frames.append(other_im) bits_used.append(bits) break else: # TODO: invent a more convenient method for proportional scalings frame = provided_im.copy() frame.thumbnail(size, Image.Resampling.LANCZOS, reducing_gap=None) frames.append(frame) fp.write(o16(len(frames))) # idCount(2) offset = fp.tell() + len(frames) * 16 for frame in frames: width, height = frame.size # 0 means 256 fp.write(o8(width if width < 256 else 0)) # bWidth(1) fp.write(o8(height if height < 256 else 0)) # bHeight(1) bits, colors = BmpImagePlugin.SAVE[frame.mode][1:] if bmp else (32, 0) fp.write(o8(colors)) # bColorCount(1) fp.write(b"\0") # bReserved(1) fp.write(b"\0\0") # wPlanes(2) fp.write(o16(bits)) # wBitCount(2) image_io = BytesIO() if bmp: frame.save(image_io, "dib") if bits != 32: and_mask = Image.new("1", size) ImageFile._save( and_mask, image_io, [("raw", (0, 0) + size, 0, ("1", 0, -1))] ) else: frame.save(image_io, "png") image_io.seek(0) image_bytes = image_io.read() if bmp: image_bytes = image_bytes[:8] + o32(height * 2) + image_bytes[12:] bytes_len = len(image_bytes) fp.write(o32(bytes_len)) # dwBytesInRes(4) fp.write(o32(offset)) # dwImageOffset(4) current = fp.tell() fp.seek(offset) fp.write(image_bytes) offset = offset + bytes_len fp.seek(current) def _accept(prefix): return prefix[:4] == _MAGIC class IcoFile: def __init__(self, buf): """ Parse image from file-like object containing ico file data """ # check magic s = buf.read(6) if not _accept(s): msg = "not an ICO file" raise SyntaxError(msg) self.buf = buf self.entry = [] # Number of items in file self.nb_items = i16(s, 4) # Get headers for each item for i in range(self.nb_items): s = buf.read(16) icon_header = { "width": s[0], "height": s[1], "nb_color": s[2], # No. of colors in image (0 if >=8bpp) "reserved": s[3], "planes": i16(s, 4), "bpp": i16(s, 6), "size": i32(s, 8), "offset": i32(s, 12), } # See Wikipedia for j in ("width", "height"): if not icon_header[j]: icon_header[j] = 256 # See Wikipedia notes about color depth. # We need this just to differ images with equal sizes icon_header["color_depth"] = ( icon_header["bpp"] or ( icon_header["nb_color"] != 0 and ceil(log(icon_header["nb_color"], 2)) ) or 256 ) icon_header["dim"] = (icon_header["width"], icon_header["height"]) icon_header["square"] = icon_header["width"] * icon_header["height"] self.entry.append(icon_header) self.entry = sorted(self.entry, key=lambda x: x["color_depth"]) # ICO images are usually squares # self.entry = sorted(self.entry, key=lambda x: x['width']) self.entry = sorted(self.entry, key=lambda x: x["square"]) self.entry.reverse() def sizes(self): """ Get a list of all available icon sizes and color depths. """ return {(h["width"], h["height"]) for h in self.entry} def getentryindex(self, size, bpp=False): for (i, h) in enumerate(self.entry): if size == h["dim"] and (bpp is False or bpp == h["color_depth"]): return i return 0 def getimage(self, size, bpp=False): """ Get an image from the icon """ return self.frame(self.getentryindex(size, bpp)) def frame(self, idx): """ Get an image from frame idx """ header = self.entry[idx] self.buf.seek(header["offset"]) data = self.buf.read(8) self.buf.seek(header["offset"]) if data[:8] == PngImagePlugin._MAGIC: # png frame im = PngImagePlugin.PngImageFile(self.buf) Image._decompression_bomb_check(im.size) else: # XOR + AND mask bmp frame im = BmpImagePlugin.DibImageFile(self.buf) Image._decompression_bomb_check(im.size) # change tile dimension to only encompass XOR image im._size = (im.size[0], int(im.size[1] / 2)) d, e, o, a = im.tile[0] im.tile[0] = d, (0, 0) + im.size, o, a # figure out where AND mask image starts bpp = header["bpp"] if 32 == bpp: # 32-bit color depth icon image allows semitransparent areas # PIL's DIB format ignores transparency bits, recover them. # The DIB is packed in BGRX byte order where X is the alpha # channel. # Back up to start of bmp data self.buf.seek(o) # extract every 4th byte (eg. 3,7,11,15,...) alpha_bytes = self.buf.read(im.size[0] * im.size[1] * 4)[3::4] # convert to an 8bpp grayscale image mask = Image.frombuffer( "L", # 8bpp im.size, # (w, h) alpha_bytes, # source chars "raw", # raw decoder ("L", 0, -1), # 8bpp inverted, unpadded, reversed ) else: # get AND image from end of bitmap w = im.size[0] if (w % 32) > 0: # bitmap row data is aligned to word boundaries w += 32 - (im.size[0] % 32) # the total mask data is # padded row size * height / bits per char total_bytes = int((w * im.size[1]) / 8) and_mask_offset = header["offset"] + header["size"] - total_bytes self.buf.seek(and_mask_offset) mask_data = self.buf.read(total_bytes) # convert raw data to image mask = Image.frombuffer( "1", # 1 bpp im.size, # (w, h) mask_data, # source chars "raw", # raw decoder ("1;I", int(w / 8), -1), # 1bpp inverted, padded, reversed ) # now we have two images, im is XOR image and mask is AND image # apply mask image as alpha channel im = im.convert("RGBA") im.putalpha(mask) return im ## # Image plugin for Windows Icon files. class IcoImageFile(ImageFile.ImageFile): """ PIL read-only image support for Microsoft Windows .ico files. By default the largest resolution image in the file will be loaded. This can be changed by altering the 'size' attribute before calling 'load'. The info dictionary has a key 'sizes' that is a list of the sizes available in the icon file. Handles classic, XP and Vista icon formats. When saving, PNG compression is used. Support for this was only added in Windows Vista. If you are unable to view the icon in Windows, convert the image to "RGBA" mode before saving. This plugin is a refactored version of Win32IconImagePlugin by Bryan Davis <casadebender@gmail.com>. https://code.google.com/archive/p/casadebender/wikis/Win32IconImagePlugin.wiki """ format = "ICO" format_description = "Windows Icon" def _open(self): self.ico = IcoFile(self.fp) self.info["sizes"] = self.ico.sizes() self.size = self.ico.entry[0]["dim"] self.load() @property def size(self): return self._size @size.setter def size(self, value): if value not in self.info["sizes"]: msg = "This is not one of the allowed sizes of this image" raise ValueError(msg) self._size = value def load(self): if self.im is not None and self.im.size == self.size: # Already loaded return Image.Image.load(self) im = self.ico.getimage(self.size) # if tile is PNG, it won't really be loaded yet im.load() self.im = im.im self.pyaccess = None self.mode = im.mode if im.size != self.size: warnings.warn("Image was not the expected size") index = self.ico.getentryindex(self.size) sizes = list(self.info["sizes"]) sizes[index] = im.size self.info["sizes"] = set(sizes) self.size = im.size def load_seek(self): # Flag the ImageFile.Parser so that it # just does all the decode at the end. pass # # -------------------------------------------------------------------- Image.register_open(IcoImageFile.format, IcoImageFile, _accept) Image.register_save(IcoImageFile.format, _save) Image.register_extension(IcoImageFile.format, ".ico") Image.register_mime(IcoImageFile.format, "image/x-icon")
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