bitmap.py

   1 # -*- encoding: utf-8 -*-
   2 #
   3 #
   4 # Copyright (C) 2004-2012 André Wobst <wobsta@users.sourceforge.net>
   5 # Copyright (C) 2011 Michael Schindler<m-schindler@users.sourceforge.net>
   6 #
   7 # This file is part of PyX (http://pyx.sourceforge.net/).
   8 #
   9 # PyX is free software; you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; either version 2 of the License, or
  12 # (at your option) any later version.
  13 #
  14 # PyX is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with PyX; if not, write to the Free Software
  21 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  22
  23 import binascii, logging, struct
  24 try:
  25     import zlib
  26     haszlib = True
  27 except:
  28     haszlib = False
  29
  30 from . import bbox, baseclasses, pswriter, pdfwriter, trafo, unit
  31
  32 logger = logging.getLogger("pyx")
  33
  34 devicenames = {"L": "/DeviceGray",
  35                "RGB": "/DeviceRGB",
  36                "CMYK": "/DeviceCMYK"}
  37 decodestrings = {"L": "[0 1]",
  38                  "RGB": "[0 1 0 1 0 1]",
  39                  "CMYK": "[0 1 0 1 0 1 0 1]",
  40                  "P": "[0 255]"}
  41
  42
  43 def ascii85lines(datalen):
  44     if datalen < 4:
  45         return 1
  46     return (datalen + 56)/60
  47
  48 def ascii85stream(file, data):
  49     """Encodes the string data in ASCII85 and writes it to
  50     the stream file. The number of lines written to the stream
  51     is known just from the length of the data by means of the
  52     ascii85lines function. Note that the tailing newline character
  53     of the last line is not added by this function, but it is taken
  54     into account in the ascii85lines function."""
  55     i = 3 # go on smoothly in case of data length equals zero
  56     l = 0
  57     l = [None, None, None, None]
  58     for i in range(len(data)):
  59         c = data[i]
  60         l[i%4] = c
  61         if i%4 == 3:
  62             if i%60 == 3 and i != 3:
  63                 file.write("\n")
  64             if l:
  65                 # instead of
  66                 # l[3], c5 = divmod(256*256*256*l[0]+256*256*l[1]+256*l[2]+l[3], 85)
  67                 # l[2], c4 = divmod(l[3], 85)
  68                 # we have to avoid number > 2**31 by
  69                 l[3], c5 = divmod(256*256*l[0]+256*256*l[1]+256*l[2]+l[3], 85)
  70                 l[2], c4 = divmod(256*256*3*l[0]+l[3], 85)
  71                 l[1], c3 = divmod(l[2], 85)
  72                 c1  , c2 = divmod(l[1], 85)
  73                 file.write_bytes(struct.pack("BBBBB", c1+33, c2+33, c3+33, c4+33, c5+33))
  74             else:
  75                 file.write("z")
  76     if i%4 != 3:
  77         for j in range((i%4) + 1, 4):
  78             l[j] = 0
  79         l[3], c5 = divmod(256*256*l[0]+256*256*l[1]+256*l[2]+l[3], 85)
  80         l[2], c4 = divmod(256*256*3*l[0]+l[3], 85)
  81         l[1], c3 = divmod(l[2], 85)
  82         c1  , c2 = divmod(l[1], 85)
  83         file.write_bytes(struct.pack("BBBB", c1+33, c2+33, c3+33, c4+33)[:(i%4)+2])
  84
  85 _asciihexlinelength = 64
  86 def asciihexlines(datalen):
  87     return (datalen*2 + _asciihexlinelength - 1) / _asciihexlinelength
  88
  89 def asciihexstream(file, data):
  90     hexdata = binascii.b2a_hex(data)
  91     for i in range((len(hexdata)-1)/_asciihexlinelength + 1):
  92         file.write(hexdata[i*_asciihexlinelength: i*_asciihexlinelength+_asciihexlinelength])
  93         file.write("\n")
  94
  95
  96 class image:
  97
  98     def __init__(self, width, height, mode, data, compressed=None, palette=None):
  99         if width <= 0 or height <= 0:
 100             raise ValueError("valid image size")
 101         if mode not in ["L", "RGB", "CMYK", "LA", "RGBA", "CMYKA", "AL", "ARGB", "ACMYK"]:
 102             raise ValueError("invalid mode")
 103         if compressed is None and len(mode)*width*height != len(data):
 104             raise ValueError("wrong size of uncompressed data")
 105         self.size = width, height
 106         self.mode = mode
 107         self.data = data
 108         self.compressed = compressed
 109         self.palette = palette
 110
 111     def split(self):
 112         if self.compressed is not None:
 113             raise RuntimeError("cannot extract bands from compressed image")
 114         bands = len(self.mode)
 115         width, height = self.size
 116         return [image(width, height, "L", "".join([self.data[i*bands+band]
 117                                                              for i in range(width*height)]))
 118                 for band in range(bands)]
 119
 120     def tobytes(self, *args):
 121         if len(args):
 122             raise RuntimeError("encoding not supported in this implementation")
 123         return self.data
 124
 125     def convert(self, model):
 126         raise RuntimeError("color model conversion not supported in this implementation")
 127
 128
 129 class jpegimage(image):
 130
 131     def __init__(self, file):
 132         try:
 133             data = file.read()
 134         except:
 135             with open(file, "rb") as f:
 136                 data = f.read()
 137         pos = 0
 138         nestinglevel = 0
 139         try:
 140             while True:
 141                 if data[pos] == 0o377 and data[pos+1] not in [0, 0o377]:
 142                     # print("marker: 0x%02x \\%03o" % (data[pos+1], data[pos+1]))
 143                     if data[pos+1] == 0o330:
 144                         if not nestinglevel:
 145                             begin = pos
 146                         nestinglevel += 1
 147                     elif not nestinglevel:
 148                         raise ValueError("begin marker expected")
 149                     elif data[pos+1] == 0o331:
 150                         nestinglevel -= 1
 151                         if not nestinglevel:
 152                             end = pos + 2
 153                             break
 154                     elif data[pos+1] in [0o300, 0o301]:
 155                         l, bits, height, width, components = struct.unpack(">HBHHB", data[pos+2:pos+10])
 156                         if bits != 8:
 157                             raise ValueError("implementation limited to 8 bit per component only")
 158                         try:
 159                             mode = {1: "L", 3: "RGB", 4: "CMYK"}[components]
 160                         except KeyError:
 161                             raise ValueError("invalid number of components")
 162                         pos += l+1
 163                     elif data[pos+1] == 0o340:
 164                         l, id, major, minor, dpikind, xdpi, ydpi = struct.unpack(">H5sBBBHH", data[pos+2:pos+16])
 165                         if dpikind == 1:
 166                             self.info = {"dpi": (xdpi, ydpi)}
 167                         elif dpikind == 2:
 168                             self.info = {"dpi": (xdpi*2.54, ydpi*2.45)}
 169                         # else do not provide dpi information
 170                         pos += l+1
 171                 pos += 1
 172         except IndexError:
 173             raise ValueError("end marker expected")
 174         image.__init__(self, width, height, mode, data[begin:end], compressed="DCT")
 175
 176
 177 class PSimagedata(pswriter.PSresource):
 178
 179     def __init__(self, name, data, singlestring, maxstrlen):
 180         pswriter.PSresource.__init__(self, "imagedata", name)
 181         self.data = data
 182         self.singlestring = singlestring
 183         self.maxstrlen = maxstrlen
 184
 185     def output(self, file, writer, registry):
 186         file.write("%%%%BeginRessource: %s\n" % self.id)
 187         if self.singlestring:
 188             file.write("%%%%BeginData: %i ASCII Lines\n"
 189                        "<~" % ascii85lines(len(self.data)))
 190             ascii85stream(file, self.data)
 191             file.write("~>\n"
 192                          "%%EndData\n")
 193         else:
 194             datalen = len(self.data)
 195             tailpos = datalen - datalen % self.maxstrlen
 196             file.write("%%%%BeginData: %i ASCII Lines\n" %
 197                        ((tailpos/self.maxstrlen) * ascii85lines(self.maxstrlen) +
 198                         ascii85lines(datalen-tailpos)))
 199             file.write("[ ")
 200             for i in range(0, tailpos, self.maxstrlen):
 201                 file.write("<~")
 202                 ascii85stream(file, self.data[i: i+self.maxstrlen])
 203                 file.write("~>\n")
 204             if datalen != tailpos:
 205                 file.write("<~")
 206                 ascii85stream(file, self.data[tailpos:])
 207                 file.write("~>")
 208             file.write("]\n"
 209                        "%%EndData\n")
 210         file.write("/%s exch def\n" % self.id)
 211         file.write("%%EndRessource\n")
 212
 213
 214 class PDFimagepalettedata(pdfwriter.PDFobject):
 215
 216     def __init__(self, name, data):
 217         pdfwriter.PDFobject.__init__(self, "imagepalettedata", name)
 218         self.data = data
 219
 220     def write(self, file, writer, registry):
 221         file.write("<<\n"
 222                    "/Length %d\n" % len(self.data))
 223         file.write(">>\n"
 224                    "stream\n")
 225         file.write(self.data)
 226         file.write("\n"
 227                    "endstream\n")
 228
 229
 230 class PDFimage(pdfwriter.PDFobject):
 231
 232     def __init__(self, name, width, height, palettemode, palettedata, mode,
 233                        bitspercomponent, compressmode, data, smask, registry, addresource=True):
 234         pdfwriter.PDFobject.__init__(self, "image", name)
 235
 236         if addresource:
 237             if palettedata is not None:
 238                 procset = "ImageI"
 239             elif mode == "L":
 240                 procset = "ImageB"
 241             else:
 242                 procset = "ImageC"
 243             registry.addresource("XObject", name, self, procset=procset)
 244         if palettedata is not None:
 245             # note that acrobat wants a palette to be an object (which clearly is a bug)
 246             self.PDFpalettedata = PDFimagepalettedata(name, palettedata)
 247             registry.add(self.PDFpalettedata)
 248
 249         self.name = name
 250         self.width = width
 251         self.height = height
 252         self.palettemode = palettemode
 253         self.palettedata = palettedata
 254         self.mode = mode
 255         self.bitspercomponent = bitspercomponent
 256         self.compressmode = compressmode
 257         self.data = data
 258         self.smask = smask
 259
 260     def write(self, file, writer, registry):
 261         file.write("<<\n"
 262                    "/Type /XObject\n"
 263                    "/Subtype /Image\n"
 264                    "/Width %d\n" % self.width)
 265         file.write("/Height %d\n" % self.height)
 266         if self.palettedata is not None:
 267             file.write("/ColorSpace [ /Indexed %s %i\n" % (devicenames[self.palettemode], len(self.palettedata)/3-1))
 268             file.write("%d 0 R\n" % registry.getrefno(self.PDFpalettedata))
 269             file.write("]\n")
 270         else:
 271             file.write("/ColorSpace %s\n" % devicenames[self.mode])
 272         if self.smask:
 273             file.write("/SMask %d 0 R\n" % registry.getrefno(self.smask))
 274         file.write("/BitsPerComponent %d\n" % self.bitspercomponent)
 275         file.write("/Length %d\n" % len(self.data))
 276         if self.compressmode:
 277             file.write("/Filter /%sDecode\n" % self.compressmode)
 278         file.write(">>\n"
 279                    "stream\n")
 280         file.write_bytes(self.data)
 281         file.write("\n"
 282                    "endstream\n")
 283
 284 class bitmap_trafo(baseclasses.canvasitem):
 285
 286     def __init__(self, trafo, image,
 287                        PSstoreimage=0, PSmaxstrlen=4093, PSbinexpand=1,
 288                        compressmode="Flate", flatecompresslevel=6,
 289                        dctquality=75, dctoptimize=0, dctprogression=0):
 290         self.pdftrafo = trafo
 291         self.image = image
 292         self.imagewidth, self.imageheight = image.size
 293
 294         self.PSstoreimage = PSstoreimage
 295         self.PSmaxstrlen = PSmaxstrlen
 296         self.PSbinexpand = PSbinexpand
 297         self.compressmode = compressmode
 298         self.flatecompresslevel = flatecompresslevel
 299         self.dctquality = dctquality
 300         self.dctoptimize = dctoptimize
 301         self.dctprogression = dctprogression
 302
 303         try:
 304             self.imagecompressed = image.compressed
 305         except:
 306             self.imagecompressed = None
 307         if self.compressmode not in [None, "Flate", "DCT"]:
 308             raise ValueError("invalid compressmode '%s'" % self.compressmode)
 309         if self.imagecompressed not in [None, "Flate", "DCT"]:
 310             raise ValueError("invalid compressed image '%s'" % self.imagecompressed)
 311         if self.compressmode is not None and self.imagecompressed is not None:
 312             raise ValueError("compression of a compressed image not supported")
 313         if not haszlib and self.compressmode == "Flate":
 314             logger.warning("zlib module not available, disable compression")
 315             self.compressmode = None
 316
 317     def imagedata(self, interleavealpha):
 318         """internal function
 319
 320         returns a tuple (mode, data, alpha, palettemode, palettedata)
 321         where mode does not contain antialiasing anymore
 322         """
 323
 324         alpha = palettemode = palettedata = None
 325         data = self.image
 326         mode = data.mode
 327         if mode.startswith("A"):
 328             mode = mode[1:]
 329             if interleavealpha:
 330                 alpha = True
 331             else:
 332                 bands = data.split()
 333                 alpha = bands[0]
 334                 data = image(self.imagewidth, self.imageheight, mode,
 335                              "".join(["".join(values)
 336                                       for values in zip(*[band.tobytes()
 337                                                           for band in bands[1:]])]), palette=data.palette)
 338         if mode.endswith("A"):
 339             bands = data.split()
 340             bands = list(bands[-1:]) + list(bands[:-1])
 341             mode = mode[:-1]
 342             if interleavealpha:
 343                 alpha = True
 344                 # TODO: this is slow, but we don't want to depend on PIL or anything ... still, its incredibly slow to do it with lists and joins
 345                 data = image(self.imagewidth, self.imageheight, "A%s" % mode,
 346                              "".join(["".join(values)
 347                                       for values in zip(*[band.tobytes()
 348                                                           for band in bands])]), palette=data.palette)
 349             else:
 350                 alpha = bands[0]
 351                 data = image(self.imagewidth, self.imageheight, mode,
 352                              "".join(["".join(values)
 353                                       for values in zip(*[band.tobytes()
 354                                                           for band in bands[1:]])]), palette=data.palette)
 355
 356         if mode == "P":
 357             palettemode, palettedata = data.palette.getdata()
 358             if palettemode not in ["L", "RGB", "CMYK"]:
 359                 logger.warning("image with unknown palette mode '%s' converted to rgb image" % palettemode)
 360                 data = data.convert("RGB")
 361                 mode = "RGB"
 362                 palettemode = None
 363                 palettedata = None
 364         elif len(mode) == 1:
 365             if mode != "L":
 366                 logger.warning("specific single channel image mode not natively supported, converted to regular grayscale")
 367                 data = data.convert("L")
 368                 mode = "L"
 369         elif mode not in ["CMYK", "RGB"]:
 370             logger.warning("image with unknown mode converted to rgb")
 371             data = data.convert("RGB")
 372             mode = "RGB"
 373
 374         if self.compressmode == "Flate":
 375             data = zlib.compress(data.tobytes(), self.flatecompresslevel)
 376         elif self.compressmode == "DCT":
 377             data = data.tobytes("jpeg", mode, self.dctquality, self.dctoptimize, self.dctprogression)
 378         else:
 379             data = data.tobytes()
 380         if alpha and not interleavealpha:
 381             if self.compressmode == "Flate":
 382                 alpha = zlib.compress(alpha.tobytes(), self.flatecompresslevel)
 383             elif self.compressmode == "DCT":
 384                 # well, this here is strange, we might want a alphacompressmode ...
 385                 alpha = alpha.tobytes("jpeg", mode, self.dctquality, self.dctoptimize, self.dctprogression)
 386             else:
 387                 alpha = alpha.tobytes()
 388
 389         return mode, data, alpha, palettemode, palettedata
 390
 391     def bbox(self):
 392         bb = bbox.empty()
 393         bb.includepoint_pt(*self.pdftrafo.apply_pt(0.0, 0.0))
 394         bb.includepoint_pt(*self.pdftrafo.apply_pt(0.0, 1.0))
 395         bb.includepoint_pt(*self.pdftrafo.apply_pt(1.0, 0.0))
 396         bb.includepoint_pt(*self.pdftrafo.apply_pt(1.0, 1.0))
 397         return bb
 398
 399     def processPS(self, file, writer, context, registry, bbox):
 400         mode, data, alpha, palettemode, palettedata = self.imagedata(True)
 401         pstrafo = trafo.translate_pt(0, -1.0).scaled(self.imagewidth, -self.imageheight)*self.pdftrafo.inverse()
 402
 403         PSsinglestring = self.PSstoreimage and len(data) < self.PSmaxstrlen
 404         if PSsinglestring:
 405             PSimagename = "image-%d-%s-singlestring" % (id(self.image), self.compressmode)
 406         else:
 407             PSimagename = "image-%d-%s-stringarray" % (id(self.image), self.compressmode)
 408
 409         if self.PSstoreimage and not PSsinglestring:
 410             registry.add(pswriter.PSdefinition("imagedataaccess",
 411                                                b"{ /imagedataindex load " # get list index
 412                                                b"dup 1 add /imagedataindex exch store " # store increased index
 413                                                b"/imagedataid load exch get }")) # select string from array
 414         if self.PSstoreimage:
 415             registry.add(PSimagedata(PSimagename, data, PSsinglestring, self.PSmaxstrlen))
 416         bbox += self.bbox()
 417
 418         file.write("gsave\n")
 419         if palettedata is not None:
 420             file.write("[ /Indexed %s %i\n" % (devicenames[palettemode], len(palettedata)/3-1))
 421             file.write("%%%%BeginData: %i ASCII Lines\n" % ascii85lines(len(palettedata)))
 422             file.write("<~")
 423             ascii85stream(file, palettedata)
 424             file.write("~>\n"
 425                        "%%EndData\n")
 426             file.write("] setcolorspace\n")
 427         else:
 428             file.write("%s setcolorspace\n" % devicenames[mode])
 429
 430         if self.PSstoreimage and not PSsinglestring:
 431             file.write("/imagedataindex 0 store\n" # not use the stack since interpreters differ in their stack usage
 432                        "/imagedataid %s store\n" % PSimagename)
 433
 434         file.write("<<\n")
 435         if alpha:
 436             file.write("/ImageType 3\n"
 437                        "/DataDict\n"
 438                        "<<\n")
 439         file.write("/ImageType 1\n"
 440                    "/Width %i\n" % self.imagewidth)
 441         file.write("/Height %i\n" % self.imageheight)
 442         file.write("/BitsPerComponent 8\n"
 443                    "/ImageMatrix %s\n" % pstrafo)
 444         file.write("/Decode %s\n" % decodestrings[mode])
 445
 446         file.write("/DataSource ")
 447         if self.PSstoreimage:
 448             if PSsinglestring:
 449                 file.write("/%s load" % PSimagename)
 450             else:
 451                 file.write("/imagedataaccess load") # some printers do not allow for inline code here -> we store it in a resource
 452         else:
 453             if self.PSbinexpand == 2:
 454                 file.write("currentfile /ASCIIHexDecode filter")
 455             else:
 456                 file.write("currentfile /ASCII85Decode filter")
 457         if self.compressmode or self.imagecompressed:
 458             file.write(" /%sDecode filter" % (self.compressmode or self.imagecompressed))
 459         file.write("\n")
 460
 461         file.write(">>\n")
 462
 463         if alpha:
 464             file.write("/MaskDict\n"
 465                        "<<\n"
 466                        "/ImageType 1\n"
 467                        "/Width %i\n" % self.imagewidth)
 468             file.write("/Height %i\n" % self.imageheight)
 469             file.write("/BitsPerComponent 8\n"
 470                        "/ImageMatrix %s\n" % pstrafo)
 471             file.write("/Decode [1 0]\n"
 472                        ">>\n"
 473                        "/InterleaveType 1\n"
 474                        ">>\n")
 475
 476         if self.PSstoreimage:
 477             file.write("image\n")
 478         else:
 479             if self.PSbinexpand == 2:
 480                 file.write("%%%%BeginData: %i ASCII Lines\n"
 481                            "image\n" % (asciihexlines(len(data)) + 1))
 482                 asciihexstream(file, data)
 483                 file.write(">\n")
 484             else:
 485                 # the datasource is currentstream (plus some filters)
 486                 file.write("%%%%BeginData: %i ASCII Lines\n"
 487                            "image\n" % (ascii85lines(len(data)) + 1))
 488                 ascii85stream(file, data)
 489                 file.write("~>\n")
 490             file.write("%%EndData\n")
 491
 492         file.write("grestore\n")
 493
 494     def processPDF(self, file, writer, context, registry, bbox):
 495         mode, data, alpha, palettemode, palettedata = self.imagedata(False)
 496
 497         name = "image-%d-%s" % (id(self.image), self.compressmode or self.imagecompressed)
 498         if alpha:
 499             alpha = PDFimage("%s-smask" % name, self.imagewidth, self.imageheight,
 500                              None, None, "L", 8,
 501                              self.compressmode, alpha, None, registry, addresource=False)
 502             registry.add(alpha)
 503         registry.add(PDFimage(name, self.imagewidth, self.imageheight,
 504                               palettemode, palettedata, mode, 8,
 505                               self.compressmode or self.imagecompressed, data, alpha, registry))
 506
 507         bbox += self.bbox()
 508
 509         file.write("q\n")
 510         self.pdftrafo.processPDF(file, writer, context, registry)
 511         file.write("/%s Do\n" % name)
 512         file.write("Q\n")
 513
 514
 515 class bitmap_pt(bitmap_trafo):
 516
 517     def __init__(self, xpos_pt, ypos_pt, image, width_pt=None, height_pt=None, ratio=None, **kwargs):
 518         imagewidth, imageheight = image.size
 519         if width_pt is not None or height_pt is not None:
 520             if width_pt is None:
 521                 if ratio is None:
 522                     width_pt = height_pt * imagewidth / float(imageheight)
 523                 else:
 524                     width_pt = ratio * height_pt
 525             elif height_pt is None:
 526                 if ratio is None:
 527                     height_pt = width_pt * imageheight / float(imagewidth)
 528                 else:
 529                     height_pt = (1.0/ratio) * width_pt
 530             elif ratio is not None:
 531                 raise ValueError("can't specify a ratio when setting width_pt and height_pt")
 532         else:
 533             if ratio is not None:
 534                 raise ValueError("must specify width_pt or height_pt to set a ratio")
 535             widthdpi, heightdpi = image.info["dpi"] # fails when no dpi information available
 536             width_pt = 72.0 * imagewidth / float(widthdpi)
 537             height_pt = 72.0 * imageheight / float(heightdpi)
 538
 539         bitmap_trafo.__init__(self, trafo.trafo_pt(((float(width_pt), 0.0), (0.0, float(height_pt))), (float(xpos_pt), float(ypos_pt))), image, **kwargs)
 540
 541
 542 class bitmap(bitmap_pt):
 543
 544     def __init__(self, xpos, ypos, image, width=None, height=None, **kwargs):
 545         xpos_pt = unit.topt(xpos)
 546         ypos_pt = unit.topt(ypos)
 547         if width is not None:
 548             width_pt = unit.topt(width)
 549         else:
 550             width_pt = None
 551         if height is not None:
 552             height_pt = unit.topt(height)
 553         else:
 554             height_pt = None
 555
 556         bitmap_pt.__init__(self, xpos_pt, ypos_pt, image, width_pt=width_pt, height_pt=height_pt, **kwargs)