pyx/bitmap.py

   1 # -*- coding: ISO-8859-1 -*-
   2 #
   3 #
   4 # Copyright (C) 2004-2006 André Wobst <wobsta@users.sourceforge.net>
   5 #
   6 # This file is part of PyX (http://pyx.sourceforge.net/).
   7 #
   8 # PyX is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 2 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # PyX is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with PyX; if not, write to the Free Software
  20 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  21
  22 import struct, warnings, binascii
  23 try:
  24     import zlib
  25     haszlib = 1
  26 except:
  27     haszlib = 0
  28
  29 import bbox, canvasitem, pswriter, pdfwriter, trafo, unit
  30
  31 def ascii85lines(datalen):
  32     if datalen < 4:
  33         return 1
  34     return (datalen + 56)/60
  35
  36 def ascii85stream(file, data):
  37     """Encodes the string data in ASCII85 and writes it to
  38     the stream file. The number of lines written to the stream
  39     is known just from the length of the data by means of the
  40     ascii85lines function. Note that the tailing newline character
  41     of the last line is not added by this function, but it is taken
  42     into account in the ascii85lines function."""
  43     i = 3 # go on smoothly in case of data length equals zero
  44     l = 0
  45     l = [None, None, None, None]
  46     for i in range(len(data)):
  47         c = data[i]
  48         l[i%4] = ord(c)
  49         if i%4 == 3:
  50             if i%60 == 3 and i != 3:
  51                 file.write("\n")
  52             if l:
  53                 # instead of
  54                 # l[3], c5 = divmod(256*256*256*l[0]+256*256*l[1]+256*l[2]+l[3], 85)
  55                 # l[2], c4 = divmod(l[3], 85)
  56                 # we have to avoid number > 2**31 by
  57                 l[3], c5 = divmod(256*256*l[0]+256*256*l[1]+256*l[2]+l[3], 85)
  58                 l[2], c4 = divmod(256*256*3*l[0]+l[3], 85)
  59                 l[1], c3 = divmod(l[2], 85)
  60                 c1  , c2 = divmod(l[1], 85)
  61                 file.write(struct.pack('BBBBB', c1+33, c2+33, c3+33, c4+33, c5+33))
  62             else:
  63                 file.write("z")
  64     if i%4 != 3:
  65         for j in range((i%4) + 1, 4):
  66             l[j] = 0
  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('BBBB', c1+33, c2+33, c3+33, c4+33)[:(i%4)+2])
  72
  73 _asciihexlinelength = 64
  74 def asciihexlines(datalen):
  75     return (datalen*2 + _asciihexlinelength - 1) / _asciihexlinelength
  76
  77 def asciihexstream(file, data):
  78     hexdata = binascii.b2a_hex(data)
  79     for i in range((len(hexdata)-1)/_asciihexlinelength + 1):
  80         file.write(hexdata[i*_asciihexlinelength: i*_asciihexlinelength+_asciihexlinelength])
  81         file.write("\n")
  82
  83
  84 class image:
  85
  86     def __init__(self, width, height, mode, data, compressed=None):
  87         if width <= 0 or height <= 0:
  88             raise ValueError("valid image size")
  89         if mode not in ["L", "RGB", "CMYK"]:
  90             raise ValueError("invalid mode")
  91         if compressed is None and len(mode)*width*height != len(data):
  92             raise ValueError("wrong size of uncompressed data")
  93         self.size = width, height
  94         self.mode = mode
  95         self.data = data
  96         self.compressed = compressed
  97
  98     def tostring(self, *args):
  99         if len(args):
 100             raise RuntimeError("encoding not supported in this implementation")
 101         return self.data
 102
 103     def convert(self, model):
 104         raise RuntimeError("color model conversion not supported in this implementation")
 105
 106
 107 class jpegimage(image):
 108
 109     def __init__(self, file):
 110         try:
 111             data = file.read()
 112         except:
 113             data = open(file, "rb").read()
 114         pos = 0
 115         nestinglevel = 0
 116         try:
 117             while 1:
 118                 if data[pos] == "\377" and data[pos+1] not in ["\0", "\377"]:
 119                     # print "marker: 0x%02x \\%03o" % (ord(data[pos+1]), ord(data[pos+1]))
 120                     if data[pos+1] == "\330":
 121                         if not nestinglevel:
 122                             begin = pos
 123                         nestinglevel += 1
 124                     elif not nestinglevel:
 125                         raise ValueError("begin marker expected")
 126                     elif data[pos+1] == "\331":
 127                         nestinglevel -= 1
 128                         if not nestinglevel:
 129                             end = pos + 2
 130                             break
 131                     elif data[pos+1] in ["\300", "\301"]:
 132                         l, bits, height, width, components = struct.unpack(">HBHHB", data[pos+2:pos+10])
 133                         if bits != 8:
 134                             raise ValueError("implementation limited to 8 bit per component only")
 135                         try:
 136                             mode = {1: "L", 3: "RGB", 4: "CMYK"}[components]
 137                         except KeyError:
 138                             raise ValueError("invalid number of components")
 139                         pos += l+1
 140                     elif data[pos+1] == "\340":
 141                         l, id, major, minor, dpikind, xdpi, ydpi = struct.unpack(">H5sBBBHH", data[pos+2:pos+16])
 142                         if dpikind == 1:
 143                             self.info = {"dpi": (xdpi, ydpi)}
 144                         elif dpikind == 2:
 145                             self.info = {"dpi": (xdpi*2.54, ydpi*2.45)}
 146                         # else do not provide dpi information
 147                         pos += l+1
 148                 pos += 1
 149         except IndexError:
 150             raise ValueError("end marker expected")
 151         image.__init__(self, width, height, mode, data[begin:end], compressed="DCT")
 152
 153
 154 class PSimagedata(pswriter.PSresource):
 155
 156     def __init__(self, name, data, singlestring, maxstrlen):
 157         pswriter.PSresource.__init__(self, "imagedata", name)
 158         self.data = data
 159         self.singlestring = singlestring
 160         self.maxstrlen = maxstrlen
 161
 162     def output(self, file, writer, registry):
 163         file.write("%%%%BeginRessource: %s\n" % self.id)
 164         if self.singlestring:
 165             file.write("%%%%BeginData: %i ASCII Lines\n"
 166                        "<~" % ascii85lines(len(self.data)))
 167             ascii85stream(file, self.data)
 168             file.write("~>\n"
 169                          "%%EndData\n")
 170         else:
 171             datalen = len(self.data)
 172             tailpos = datalen - datalen % self.maxstrlen
 173             file.write("%%%%BeginData: %i ASCII Lines\n" %
 174                        ((tailpos/self.maxstrlen) * ascii85lines(self.maxstrlen) +
 175                         ascii85lines(datalen-tailpos)))
 176             file.write("[ ")
 177             for i in xrange(0, tailpos, self.maxstrlen):
 178                 file.write("<~")
 179                 ascii85stream(file, self.data[i: i+self.maxstrlen])
 180                 file.write("~>\n")
 181             if datalen != tailpos:
 182                 file.write("<~")
 183                 ascii85stream(file, self.data[tailpos:])
 184                 file.write("~>")
 185             file.write("]\n"
 186                        "%%EndData\n")
 187         file.write("/%s exch def\n" % self.id)
 188         file.write("%%EndRessource\n")
 189
 190
 191 class PDFimagepalettedata(pdfwriter.PDFobject):
 192
 193     def __init__(self, name, data):
 194         pdfwriter.PDFobject.__init__(self, "imagepalettedata", name)
 195         self.data = data
 196
 197     def write(self, file, writer, registry):
 198         file.write("<<\n"
 199                    "/Length %d\n" % len(self.data))
 200         file.write(">>\n"
 201                    "stream\n")
 202         file.write(self.data)
 203         file.write("\n"
 204                    "endstream\n")
 205
 206
 207 class PDFimage(pdfwriter.PDFobject):
 208
 209     def __init__(self, name, width, height, palettecolorspace, palettedata, colorspace,
 210                        bitspercomponent, compressmode, data, registry):
 211         if palettedata is not None:
 212             procset = "ImageI"
 213         elif colorspace == "/DeviceGray":
 214             procset = "ImageB"
 215         else:
 216             procset = "ImageC"
 217         pdfwriter.PDFobject.__init__(self, "image", name)
 218         registry.addresource("XObject", name, self, procset=procset)
 219         if palettedata is not None:
 220             # acrobat wants a palette to be an object
 221             self.PDFpalettedata = PDFimagepalettedata(name, palettedata)
 222             registry.add(self.PDFpalettedata)
 223         self.name = name
 224         self.width = width
 225         self.height = height
 226         self.palettecolorspace = palettecolorspace
 227         self.palettedata = palettedata
 228         self.colorspace = colorspace
 229         self.bitspercomponent = bitspercomponent
 230         self.compressmode = compressmode
 231         self.data = data
 232
 233     def write(self, file, writer, registry):
 234         file.write("<<\n"
 235                    "/Type /XObject\n"
 236                    "/Subtype /Image\n"
 237                    "/Width %d\n" % self.width)
 238         file.write("/Height %d\n" % self.height)
 239         if self.palettedata is not None:
 240             file.write("/ColorSpace [ /Indexed %s %i\n" % (self.palettecolorspace, len(self.palettedata)/3-1))
 241             file.write("%d 0 R\n" % registry.getrefno(self.PDFpalettedata))
 242             file.write("]\n")
 243         else:
 244             file.write("/ColorSpace %s\n" % self.colorspace)
 245         file.write("/BitsPerComponent %d\n" % self.bitspercomponent)
 246         file.write("/Length %d\n" % len(self.data))
 247         if self.compressmode:
 248             file.write("/Filter /%sDecode\n" % self.compressmode)
 249         file.write(">>\n"
 250                    "stream\n")
 251         file.write(self.data)
 252         file.write("\n"
 253                    "endstream\n")
 254
 255
 256 class bitmap(canvasitem.canvasitem):
 257
 258     def __init__(self, xpos, ypos, image, width=None, height=None, ratio=None,
 259                        PSstoreimage=0, PSmaxstrlen=4093, PSbinexpand=1,
 260                        compressmode="Flate", flatecompresslevel=6,
 261                        dctquality=75, dctoptimize=0, dctprogression=0):
 262         # keep a copy of the image instance to ensure different id's
 263         self.image = image
 264
 265         self.xpos = xpos
 266         self.ypos = ypos
 267         self.imagewidth, self.imageheight = image.size
 268         self.PSstoreimage = PSstoreimage
 269         self.PSmaxstrlen = PSmaxstrlen
 270         self.PSbinexpand = PSbinexpand
 271
 272         if width is not None or height is not None:
 273             self.width = width
 274             self.height = height
 275             if self.width is None:
 276                 if ratio is None:
 277                     self.width = self.height * self.imagewidth / float(self.imageheight)
 278                 else:
 279                     self.width = ratio * self.height
 280             elif self.height is None:
 281                 if ratio is None:
 282                     self.height = self.width * self.imageheight / float(self.imagewidth)
 283                 else:
 284                     self.height = (1.0/ratio) * self.width
 285             elif ratio is not None:
 286                 raise ValueError("can't specify a ratio when setting width and height")
 287         else:
 288             if ratio is not None:
 289                 raise ValueError("must specify width or height to set a ratio")
 290             widthdpi, heightdpi = image.info["dpi"] # fails when no dpi information available
 291             self.width = self.imagewidth / float(widthdpi) * unit.t_inch
 292             self.height = self.imageheight / float(heightdpi) * unit.t_inch
 293
 294         self.xpos_pt = unit.topt(self.xpos)
 295         self.ypos_pt = unit.topt(self.ypos)
 296         self.width_pt = unit.topt(self.width)
 297         self.height_pt = unit.topt(self.height)
 298
 299         # create decode and colorspace
 300         self.colorspace = self.palettecolorspace = self.palettedata = None
 301         if image.mode == "P":
 302             palettemode, self.palettedata = image.palette.getdata()
 303             self.decode = "[0 255]"
 304             try:
 305                 self.palettecolorspace = {"L": "/DeviceGray",
 306                                           "RGB": "/DeviceRGB",
 307                                           "CMYK": "/DeviceCMYK"}[palettemode]
 308             except KeyError:
 309                 warnings.warn("image with unknown palette mode '%s' converted to rgb image" % palettemode)
 310                 image = image.convert("RGB")
 311                 self.decode = "[0 1 0 1 0 1]"
 312                 self.palettedata = None
 313                 self.colorspace = "/DeviceRGB"
 314         elif len(image.mode) == 1:
 315             if image.mode != "L":
 316                 image = image.convert("L")
 317                 warnings.warn("specific single channel image mode not natively supported, converted to regular grayscale")
 318             self.decode = "[0 1]"
 319             self.colorspace = "/DeviceGray"
 320         elif image.mode == "CMYK":
 321             self.decode = "[0 1 0 1 0 1 0 1]"
 322             self.colorspace = "/DeviceCMYK"
 323         else:
 324             if image.mode != "RGB":
 325                 image = image.convert("RGB")
 326                 warnings.warn("image with unknown mode converted to rgb")
 327             self.decode = "[0 1 0 1 0 1]"
 328             self.colorspace = "/DeviceRGB"
 329
 330         # create imagematrix
 331         self.imagematrixPS = (trafo.mirror(0)
 332                               .translated_pt(-self.xpos_pt, self.ypos_pt+self.height_pt)
 333                               .scaled_pt(self.imagewidth/self.width_pt, self.imageheight/self.height_pt))
 334         self.imagematrixPDF = (trafo.scale_pt(self.width_pt, self.height_pt)
 335                                .translated_pt(self.xpos_pt, self.ypos_pt))
 336
 337         # check whether imagedata is compressed or not
 338         try:
 339             imagecompressed = image.compressed
 340         except:
 341             imagecompressed = None
 342         if compressmode != None and imagecompressed != None:
 343             raise ValueError("compression of a compressed image not supported")
 344         self.compressmode = compressmode
 345         if compressmode is not None and compressmode not in ["Flate", "DCT"]:
 346                 raise ValueError("invalid compressmode '%s'" % compressmode)
 347         if imagecompressed is not None:
 348             self.compressmode = imagecompressed
 349             if imagecompressed not in ["Flate", "DCT"]:
 350                 raise ValueError("invalid compressed image '%s'" % imagecompressed)
 351         if not haszlib and compressmode == "Flate":
 352             warnings.warn("zlib module not available, disable compression")
 353             self.compressmode = compressmode = None
 354
 355         # create data
 356         if compressmode == "Flate":
 357             self.data = zlib.compress(image.tostring(), flatecompresslevel)
 358         elif compressmode == "DCT":
 359             self.data = image.tostring("jpeg", image.mode,
 360                                        dctquality, dctoptimize, dctprogression)
 361         else:
 362             self.data = image.tostring()
 363
 364         self.PSsinglestring = self.PSstoreimage and len(self.data) < self.PSmaxstrlen
 365         if self.PSsinglestring:
 366             self.PSimagename = "image-%d-%s-singlestring" % (id(image), compressmode)
 367         else:
 368             self.PSimagename = "image-%d-%s-stringarray" % (id(image), compressmode)
 369         self.PDFimagename = "image-%d-%s" % (id(image), compressmode)
 370
 371     def bbox(self):
 372         return bbox.bbox_pt(self.xpos_pt, self.ypos_pt,
 373                             self.xpos_pt+self.width_pt, self.ypos_pt+self.height_pt)
 374
 375     def processPS(self, file, writer, context, registry, bbox):
 376         if self.PSstoreimage and not self.PSsinglestring:
 377             registry.add(pswriter.PSdefinition("imagedataaccess",
 378                                                "{ /imagedataindex load " # get list index
 379                                                "dup 1 add /imagedataindex exch store " # store increased index
 380                                                "/imagedataid load exch get }")) # select string from array
 381         if self.PSstoreimage:
 382             registry.add(PSimagedata(self.PSimagename, self.data, self.PSsinglestring, self.PSmaxstrlen))
 383         bbox += self.bbox()
 384
 385         file.write("gsave\n")
 386         if self.palettedata is not None:
 387             file.write("[ /Indexed %s %i\n" % (self.palettecolorspace, len(self.palettedata)/3-1))
 388             file.write("%%%%BeginData: %i ASCII Lines\n" % ascii85lines(len(self.palettedata)))
 389             file.write("<~")
 390             ascii85stream(file, self.palettedata)
 391             file.write("~>\n"
 392                        "%%EndData\n")
 393             file.write("] setcolorspace\n")
 394         else:
 395             file.write("%s setcolorspace\n" % self.colorspace)
 396
 397         if self.PSstoreimage and not self.PSsinglestring:
 398             file.write("/imagedataindex 0 store\n" # not use the stack since interpreters differ in their stack usage
 399                        "/imagedataid %s store\n" % self.PSimagename)
 400
 401         file.write("<<\n"
 402                    "/ImageType 1\n"
 403                    "/Width %i\n" % self.imagewidth)
 404         file.write("/Height %i\n" % self.imageheight)
 405         file.write("/BitsPerComponent 8\n"
 406                    "/ImageMatrix %s\n" % self.imagematrixPS)
 407         file.write("/Decode %s\n" % self.decode)
 408
 409         file.write("/DataSource ")
 410         if self.PSstoreimage:
 411             if self.PSsinglestring:
 412                 file.write("/%s load" % self.PSimagename)
 413             else:
 414                 file.write("/imagedataaccess load") # some printers do not allow for inline code here -> we store it in a resource
 415         else:
 416             if self.PSbinexpand == 2:
 417                 file.write("currentfile /ASCIIHexDecode filter")
 418             else:
 419                 file.write("currentfile /ASCII85Decode filter")
 420         if self.compressmode:
 421             file.write(" /%sDecode filter" % self.compressmode)
 422         file.write("\n")
 423
 424         file.write(">>\n")
 425
 426         if self.PSstoreimage:
 427             file.write("image\n")
 428         else:
 429             if self.PSbinexpand == 2:
 430                 file.write("%%%%BeginData: %i ASCII Lines\n"
 431                            "image\n" % (asciihexlines(len(self.data)) + 1))
 432                 asciihexstream(file, self.data)
 433             else:
 434                 # the datasource is currentstream (plus some filters)
 435                 file.write("%%%%BeginData: %i ASCII Lines\n"
 436                            "image\n" % (ascii85lines(len(self.data)) + 1))
 437                 ascii85stream(file, self.data)
 438                 file.write("~>\n")
 439             file.write("%%EndData\n")
 440
 441         file.write("grestore\n")
 442
 443     def processPDF(self, file, writer, context, registry, bbox):
 444         registry.add(PDFimage(self.PDFimagename, self.imagewidth, self.imageheight,
 445                               self.palettecolorspace, self.palettedata, self.colorspace,
 446                               8, self.compressmode, self.data, registry))
 447         bbox += self.bbox()
 448
 449         file.write("q\n")
 450         self.imagematrixPDF.processPDF(file, writer, context, registry, bbox)
 451         file.write("/%s Do\n" % self.PDFimagename)
 452         file.write("Q\n")