Source code for PIL.IcnsImagePlugin

#
# The Python Imaging Library.
# $Id$
#
# Mac OS X icns file decoder, based on icns.py by Bob Ippolito.
#
# history:
# 2004-10-09 fl   Turned into a PIL plugin; removed 2.3 dependencies.
#
# Copyright (c) 2004 by Bob Ippolito.
# Copyright (c) 2004 by Secret Labs.
# Copyright (c) 2004 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#

from PIL import Image, ImageFile, _binary
import struct

i8 = _binary.i8

HEADERSIZE = 8

[docs]def nextheader(fobj): return struct.unpack('>4sI', fobj.read(HEADERSIZE))
[docs]def read_32t(fobj, start_length, size): # The 128x128 icon seems to have an extra header for some reason. (start, length) = start_length fobj.seek(start) sig = fobj.read(4) if sig != b'\x00\x00\x00\x00': raise SyntaxError('Unknown signature, expecting 0x00000000') return read_32(fobj, (start + 4, length - 4), size)
[docs]def read_32(fobj, start_length, size): """ Read a 32bit RGB icon resource. Seems to be either uncompressed or an RLE packbits-like scheme. """ (start, length) = start_length fobj.seek(start) sizesq = size[0] * size[1] if length == sizesq * 3: # uncompressed ("RGBRGBGB") indata = fobj.read(length) im = Image.frombuffer("RGB", size, indata, "raw", "RGB", 0, 1) else: # decode image im = Image.new("RGB", size, None) for band_ix in range(3): data = [] bytesleft = sizesq while bytesleft > 0: byte = fobj.read(1) if not byte: break byte = i8(byte) if byte & 0x80: blocksize = byte - 125 byte = fobj.read(1) for i in range(blocksize): data.append(byte) else: blocksize = byte + 1 data.append(fobj.read(blocksize)) bytesleft = bytesleft - blocksize if bytesleft <= 0: break if bytesleft != 0: raise SyntaxError( "Error reading channel [%r left]" % bytesleft ) band = Image.frombuffer( "L", size, b"".join(data), "raw", "L", 0, 1 ) im.im.putband(band.im, band_ix) return {"RGB": im}
[docs]def read_mk(fobj, start_length, size): # Alpha masks seem to be uncompressed (start, length) = start_length fobj.seek(start) band = Image.frombuffer( "L", size, fobj.read(size[0]*size[1]), "raw", "L", 0, 1 ) return {"A": band}
[docs]class IcnsFile: SIZES = { (128, 128): [ (b'it32', read_32t), (b't8mk', read_mk), ], (48, 48): [ (b'ih32', read_32), (b'h8mk', read_mk), ], (32, 32): [ (b'il32', read_32), (b'l8mk', read_mk), ], (16, 16): [ (b'is32', read_32), (b's8mk', read_mk), ], } def __init__(self, fobj): """ fobj is a file-like object as an icns resource """ # signature : (start, length) self.dct = dct = {} self.fobj = fobj sig, filesize = nextheader(fobj) if sig != 'icns': raise SyntaxError('not an icns file') i = HEADERSIZE while i < filesize: sig, blocksize = nextheader(fobj) i = i + HEADERSIZE blocksize = blocksize - HEADERSIZE dct[sig] = (i, blocksize) fobj.seek(blocksize, 1) i = i + blocksize
[docs] def itersizes(self): sizes = [] for size, fmts in self.SIZES.items(): for (fmt, reader) in fmts: if fmt in self.dct: sizes.append(size) break return sizes
[docs] def bestsize(self): sizes = self.itersizes() if not sizes: raise SyntaxError("No 32bit icon resources found") return max(sizes)
[docs] def dataforsize(self, size): """ Get an icon resource as {channel: array}. Note that the arrays are bottom-up like windows bitmaps and will likely need to be flipped or transposed in some way. """ dct = {} for code, reader in self.SIZES[size]: desc = self.dct.get(code) if desc is not None: dct.update(reader(self.fobj, desc, size)) return dct
[docs] def getimage(self, size=None): if size is None: size = self.bestsize() channels = self.dataforsize(size) im = channels.get("RGB").copy() try: im.putalpha(channels["A"]) except KeyError: pass return im ## # Image plugin for Mac OS icons.
[docs]class IcnsImageFile(ImageFile.ImageFile): """ PIL read-only image support for Mac OS .icns files. Chooses the best resolution, but will possibly load a different size image if you mutate the size attribute before calling 'load'. The info dictionary has a key 'sizes' that is a list of sizes that the icns file has. """ format = "ICNS" format_description = "Mac OS icns resource" def _open(self): self.icns = IcnsFile(self.fp) self.mode = 'RGBA' self.size = self.icns.bestsize() self.info['sizes'] = self.icns.itersizes() # Just use this to see if it's loaded or not yet. self.tile = ('',)
[docs] def load(self): Image.Image.load(self) if not self.tile: return self.load_prepare() # This is likely NOT the best way to do it, but whatever. im = self.icns.getimage(self.size) self.im = im.im self.mode = im.mode self.size = im.size self.fp = None self.icns = None self.tile = () self.load_end()
Image.register_open("ICNS", IcnsImageFile, lambda x: x[:4] == b'icns') Image.register_extension("ICNS", '.icns') if __name__ == '__main__': import os, sys im = Image.open(open(sys.argv[1], "rb")) im.save("out.png") os.startfile("out.png")