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diff --git a/PdfFileTransformer/PyPDF2/filters.py b/PdfFileTransformer/PyPDF2/filters.py
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+# vim: sw=4:expandtab:foldmethod=marker
+#
+# Copyright (c) 2006, Mathieu Fenniak
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# * Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+# * The name of the author may not be used to endorse or promote products
+# derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+
+"""
+Implementation of stream filters for PDF.
+"""
+__author__ = "Mathieu Fenniak"
+__author_email__ = "biziqe@mathieu.fenniak.net"
+
+import math
+
+from .utils import PdfReadError, ord_, chr_, paethPredictor
+from sys import version_info
+if version_info < ( 3, 0 ):
+    from cStringIO import StringIO
+else:
+    from io import StringIO
+    import struct
+
+try:
+    import zlib
+
+    def decompress(data):
+        return zlib.decompress(data)
+
+    def compress(data):
+        return zlib.compress(data)
+
+except ImportError:
+    # Unable to import zlib.  Attempt to use the System.IO.Compression
+    # library from the .NET framework. (IronPython only)
+    import System
+    from System import IO, Collections, Array
+
+    def _string_to_bytearr(buf):
+        retval = Array.CreateInstance(System.Byte, len(buf))
+        for i in range(len(buf)):
+            retval[i] = ord(buf[i])
+        return retval
+
+    def _bytearr_to_string(bytes):
+        retval = ""
+        for i in range(bytes.Length):
+            retval += chr(bytes[i])
+        return retval
+
+    def _read_bytes(stream):
+        ms = IO.MemoryStream()
+        buf = Array.CreateInstance(System.Byte, 2048)
+        while True:
+            bytes = stream.Read(buf, 0, buf.Length)
+            if bytes == 0:
+                break
+            else:
+                ms.Write(buf, 0, bytes)
+        retval = ms.ToArray()
+        ms.Close()
+        return retval
+
+    def decompress(data):
+        bytes = _string_to_bytearr(data)
+        ms = IO.MemoryStream()
+        ms.Write(bytes, 0, bytes.Length)
+        ms.Position = 0  # fseek 0
+        gz = IO.Compression.DeflateStream(ms, IO.Compression.CompressionMode.Decompress)
+        bytes = _read_bytes(gz)
+        retval = _bytearr_to_string(bytes)
+        gz.Close()
+        return retval
+
+    def compress(data):
+        bytes = _string_to_bytearr(data)
+        ms = IO.MemoryStream()
+        gz = IO.Compression.DeflateStream(ms, IO.Compression.CompressionMode.Compress, True)
+        gz.Write(bytes, 0, bytes.Length)
+        gz.Close()
+        ms.Position = 0 # fseek 0
+        bytes = ms.ToArray()
+        retval = _bytearr_to_string(bytes)
+        ms.Close()
+        return retval
+
+
+class FlateDecode(object):
+    def decode(data, decodeParms):
+        data = decompress(data)
+        predictor = 1
+        if decodeParms:
+            try:
+                predictor = decodeParms.get("/Predictor", 1)
+            except AttributeError:
+                pass    # usually an array with a null object was read
+
+        # predictor 1 == no predictor
+        if predictor != 1:
+            columns = decodeParms["/Columns"]
+            # PNG prediction:
+            if predictor >= 10 and predictor <= 15:
+                output = StringIO()
+                # PNG prediction can vary from row to row
+                rowlength = columns + 1
+                assert len(data) % rowlength == 0
+                prev_rowdata = (0,) * rowlength
+                for row in range(len(data) // rowlength):
+                    rowdata = [ord_(x) for x in data[(row*rowlength):((row+1)*rowlength)]]
+                    filterByte = rowdata[0]
+                    if filterByte == 0:
+                        pass
+                    elif filterByte == 1:
+                        for i in range(2, rowlength):
+                            rowdata[i] = (rowdata[i] + rowdata[i-1]) % 256
+                    elif filterByte == 2:
+                        for i in range(1, rowlength):
+                            rowdata[i] = (rowdata[i] + prev_rowdata[i]) % 256
+                    elif filterByte == 3:
+                        for i in range(1, rowlength):
+                            left = rowdata[i-1] if i > 1 else 0
+                            floor = math.floor(left + prev_rowdata[i])/2
+                            rowdata[i] = (rowdata[i] + int(floor)) % 256
+                    elif filterByte == 4:
+                        for i in range(1, rowlength):
+                            left = rowdata[i - 1] if i > 1 else 0
+                            up = prev_rowdata[i]
+                            up_left = prev_rowdata[i - 1] if i > 1 else 0
+                            paeth = paethPredictor(left, up, up_left)
+                            rowdata[i] = (rowdata[i] + paeth) % 256
+                    else:
+                        # unsupported PNG filter
+                        raise PdfReadError("Unsupported PNG filter %r" % filterByte)
+                    prev_rowdata = rowdata
+                    output.write(''.join([chr(x) for x in rowdata[1:]]))
+                data = output.getvalue()
+            else:
+                # unsupported predictor
+                raise PdfReadError("Unsupported flatedecode predictor %r" % predictor)
+        return data
+    decode = staticmethod(decode)
+
+    def encode(data):
+        return compress(data)
+    encode = staticmethod(encode)
+
+
+class ASCIIHexDecode(object):
+    def decode(data, decodeParms=None):
+        retval = ""
+        char = ""
+        x = 0
+        while True:
+            c = data[x]
+            if c == ">":
+                break
+            elif c.isspace():
+                x += 1
+                continue
+            char += c
+            if len(char) == 2:
+                retval += chr(int(char, base=16))
+                char = ""
+            x += 1
+        assert char == ""
+        return retval
+    decode = staticmethod(decode)
+
+
+class LZWDecode(object):
+    """Taken from:
+    http://www.java2s.com/Open-Source/Java-Document/PDF/PDF-Renderer/com/sun/pdfview/decode/LZWDecode.java.htm
+    """
+    class decoder(object):
+        def __init__(self, data):
+            self.STOP=257
+            self.CLEARDICT=256
+            self.data=data
+            self.bytepos=0
+            self.bitpos=0
+            self.dict=[""]*4096
+            for i in range(256):
+                self.dict[i]=chr(i)
+            self.resetDict()
+
+        def resetDict(self):
+            self.dictlen=258
+            self.bitspercode=9
+
+        def nextCode(self):
+            fillbits=self.bitspercode
+            value=0
+            while fillbits>0 :
+                if self.bytepos >= len(self.data):
+                    return -1
+                nextbits=ord_(self.data[self.bytepos])
+                bitsfromhere=8-self.bitpos
+                if bitsfromhere>fillbits:
+                    bitsfromhere=fillbits
+                value |= (((nextbits >> (8-self.bitpos-bitsfromhere)) &
+                           (0xff >> (8-bitsfromhere))) <<
+                          (fillbits-bitsfromhere))
+                fillbits -= bitsfromhere
+                self.bitpos += bitsfromhere
+                if self.bitpos >=8:
+                    self.bitpos=0
+                    self.bytepos = self.bytepos+1
+            return value
+
+        def decode(self):
+            """ algorithm derived from:
+            http://www.rasip.fer.hr/research/compress/algorithms/fund/lz/lzw.html
+            and the PDFReference
+            """
+            cW = self.CLEARDICT;
+            baos=""
+            while True:
+                pW = cW;
+                cW = self.nextCode();
+                if cW == -1:
+                    raise PdfReadError("Missed the stop code in LZWDecode!")
+                if cW == self.STOP:
+                    break;
+                elif cW == self.CLEARDICT:
+                    self.resetDict();
+                elif pW == self.CLEARDICT:
+                    baos+=self.dict[cW]
+                else:
+                    if cW < self.dictlen:
+                        baos += self.dict[cW]
+                        p=self.dict[pW]+self.dict[cW][0]
+                        self.dict[self.dictlen]=p
+                        self.dictlen+=1
+                    else:
+                        p=self.dict[pW]+self.dict[pW][0]
+                        baos+=p
+                        self.dict[self.dictlen] = p;
+                        self.dictlen+=1
+                    if (self.dictlen >= (1 << self.bitspercode) - 1 and
+                        self.bitspercode < 12):
+                        self.bitspercode+=1
+            return baos
+
+    @staticmethod
+    def decode(data,decodeParams=None):
+        return LZWDecode.decoder(data).decode()
+
+
+class ASCII85Decode(object):
+    def decode(data, decodeParms=None):
+        if version_info < ( 3, 0 ):
+            retval = ""
+            group = []
+            x = 0
+            hitEod = False
+            # remove all whitespace from data
+            data = [y for y in data if not (y in ' \n\r\t')]
+            while not hitEod:
+                c = data[x]
+                if len(retval) == 0 and c == "<" and data[x+1] == "~":
+                    x += 2
+                    continue
+                #elif c.isspace():
+                #    x += 1
+                #    continue
+                elif c == 'z':
+                    assert len(group) == 0
+                    retval += '\x00\x00\x00\x00'
+                    x += 1
+                    continue
+                elif c == "~" and data[x+1] == ">":
+                    if len(group) != 0:
+                        # cannot have a final group of just 1 char
+                        assert len(group) > 1
+                        cnt = len(group) - 1
+                        group += [ 85, 85, 85 ]
+                        hitEod = cnt
+                    else:
+                        break
+                else:
+                    c = ord(c) - 33
+                    assert c >= 0 and c < 85
+                    group += [ c ]
+                if len(group) >= 5:
+                    b = group[0] * (85**4) + \
+                        group[1] * (85**3) + \
+                        group[2] * (85**2) + \
+                        group[3] * 85 + \
+                        group[4]
+                    assert b < (2**32 - 1)
+                    c4 = chr((b >> 0) % 256)
+                    c3 = chr((b >> 8) % 256)
+                    c2 = chr((b >> 16) % 256)
+                    c1 = chr(b >> 24)
+                    retval += (c1 + c2 + c3 + c4)
+                    if hitEod:
+                        retval = retval[:-4+hitEod]
+                    group = []
+                x += 1
+            return retval
+        else:
+            if isinstance(data, str):
+                data = data.encode('ascii')
+            n = b = 0
+            out = bytearray()
+            for c in data:
+                if ord('!') <= c and c <= ord('u'):
+                    n += 1
+                    b = b*85+(c-33)
+                    if n == 5:
+                        out += struct.pack(b'>L',b)
+                        n = b = 0
+                elif c == ord('z'):
+                    assert n == 0
+                    out += b'\0\0\0\0'
+                elif c == ord('~'):
+                    if n:
+                        for _ in range(5-n):
+                            b = b*85+84
+                        out += struct.pack(b'>L',b)[:n-1]
+                    break
+            return bytes(out)
+    decode = staticmethod(decode)
+
+class DCTDecode(object):
+    def decode(data, decodeParms=None):
+        return data
+    decode = staticmethod(decode)
+    
+class JPXDecode(object):
+    def decode(data, decodeParms=None):
+        return data
+    decode = staticmethod(decode)
+    
+class CCITTFaxDecode(object):   
+    def decode(data, decodeParms=None, height=0):
+        if decodeParms:
+            if decodeParms.get("/K", 1) == -1:
+                CCITTgroup = 4
+            else:
+                CCITTgroup = 3
+        
+        width = decodeParms["/Columns"]
+        imgSize = len(data)
+        tiff_header_struct = '<' + '2s' + 'h' + 'l' + 'h' + 'hhll' * 8 + 'h'
+        tiffHeader = struct.pack(tiff_header_struct,
+                           b'II',  # Byte order indication: Little endian
+                           42,  # Version number (always 42)
+                           8,  # Offset to first IFD
+                           8,  # Number of tags in IFD
+                           256, 4, 1, width,  # ImageWidth, LONG, 1, width
+                           257, 4, 1, height,  # ImageLength, LONG, 1, length
+                           258, 3, 1, 1,  # BitsPerSample, SHORT, 1, 1
+                           259, 3, 1, CCITTgroup,  # Compression, SHORT, 1, 4 = CCITT Group 4 fax encoding
+                           262, 3, 1, 0,  # Thresholding, SHORT, 1, 0 = WhiteIsZero
+                           273, 4, 1, struct.calcsize(tiff_header_struct),  # StripOffsets, LONG, 1, length of header
+                           278, 4, 1, height,  # RowsPerStrip, LONG, 1, length
+                           279, 4, 1, imgSize,  # StripByteCounts, LONG, 1, size of image
+                           0  # last IFD
+                           )
+        
+        return tiffHeader + data
+    
+    decode = staticmethod(decode)
+    
+def decodeStreamData(stream):
+    from .generic import NameObject
+    filters = stream.get("/Filter", ())
+
+    if len(filters) and not isinstance(filters[0], NameObject):
+        # we have a single filter instance
+        filters = (filters,)
+    data = stream._data
+    # If there is not data to decode we should not try to decode the data.
+    if data:
+        for filterType in filters:
+            if filterType == "/FlateDecode" or filterType == "/Fl":
+                data = FlateDecode.decode(data, stream.get("/DecodeParms"))
+            elif filterType == "/ASCIIHexDecode" or filterType == "/AHx":
+                data = ASCIIHexDecode.decode(data)
+            elif filterType == "/LZWDecode" or filterType == "/LZW":
+                data = LZWDecode.decode(data, stream.get("/DecodeParms"))
+            elif filterType == "/ASCII85Decode" or filterType == "/A85":
+                data = ASCII85Decode.decode(data)
+            elif filterType == "/DCTDecode":
+                data = DCTDecode.decode(data)
+            elif filterType == "/JPXDecode":
+                data = JPXDecode.decode(data)
+            elif filterType == "/CCITTFaxDecode":
+                height = stream.get("/Height", ())
+                data = CCITTFaxDecode.decode(data, stream.get("/DecodeParms"), height)
+            elif filterType == "/Crypt":
+                decodeParams = stream.get("/DecodeParams", {})
+                if "/Name" not in decodeParams and "/Type" not in decodeParams:
+                    pass
+                else:
+                    raise NotImplementedError("/Crypt filter with /Name or /Type not supported yet")
+            else:
+                # unsupported filter
+                raise NotImplementedError("unsupported filter %s" % filterType)
+    return data