pyx/bitmap.py

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