/**
* Decode a byte[] applying the filters specified in the provided dictionary.
* @param b the bytes to decode
* @param streamDictionary the dictionary that contains filter information
* @return the decoded bytes
* @throws IOException if there are any problems decoding the bytes
* @since 5.0.4
*/
public static byte[] DecodeBytes(byte[] b, PdfDictionary streamDictionary) {
PdfObject filter = GetPdfObjectRelease(streamDictionary.Get(PdfName.FILTER));
List<PdfObject> filters = new List<PdfObject>();
if (filter != null) {
if (filter.IsName())
filters.Add(filter);
else if (filter.IsArray())
filters = ((PdfArray)filter).ArrayList;
}
List<PdfObject> dp = new List<PdfObject>();
PdfObject dpo = GetPdfObjectRelease(streamDictionary.Get(PdfName.DECODEPARMS));
if (dpo == null || (!dpo.IsDictionary() && !dpo.IsArray()))
dpo = GetPdfObjectRelease(streamDictionary.Get(PdfName.DP));
if (dpo != null) {
if (dpo.IsDictionary())
dp.Add(dpo);
else if (dpo.IsArray())
dp = ((PdfArray)dpo).ArrayList;
}
PdfName name;
for (int j = 0; j < filters.Count; ++j) {
name = ((PdfName)GetPdfObjectRelease(filters[j]));
if (PdfName.FLATEDECODE.Equals(name) || PdfName.FL.Equals(name)) {
b = FlateDecode(b);
PdfObject dicParam = null;
if (j < dp.Count) {
dicParam = (PdfObject)dp[j];
b = DecodePredictor(b, dicParam);
}
}
else if (PdfName.ASCIIHEXDECODE.Equals(name) || PdfName.AHX.Equals(name))
b = ASCIIHexDecode(b);
else if (PdfName.ASCII85DECODE.Equals(name) || PdfName.A85.Equals(name))
b = ASCII85Decode(b);
else if (PdfName.LZWDECODE.Equals(name)) {
b = LZWDecode(b);
PdfObject dicParam = null;
if (j < dp.Count) {
dicParam = (PdfObject)dp[j];
b = DecodePredictor(b, dicParam);
}
}
else if (PdfName.CCITTFAXDECODE.Equals(name)) {
PdfNumber wn = (PdfNumber)GetPdfObjectRelease(streamDictionary.Get(PdfName.WIDTH));
PdfNumber hn = (PdfNumber)GetPdfObjectRelease(streamDictionary.Get(PdfName.HEIGHT));
if (wn == null || hn == null)
throw new UnsupportedPdfException(MessageLocalization.GetComposedMessage("filter.ccittfaxdecode.is.only.supported.for.images"));
int width = wn.IntValue;
int height = hn.IntValue;
PdfDictionary param = null;
if (j < dp.Count) {
PdfObject objParam = GetPdfObjectRelease((PdfObject)dp[j]);
if (objParam != null && (objParam is PdfDictionary))
param = (PdfDictionary)objParam;
}
int k = 0;
bool blackIs1 = false;
bool byteAlign = false;
if (param != null) {
PdfNumber kn = param.GetAsNumber(PdfName.K);
if (kn != null)
k = kn.IntValue;
PdfBoolean bo = param.GetAsBoolean(PdfName.BLACKIS1);
if (bo != null)
blackIs1 = bo.BooleanValue;
bo = param.GetAsBoolean(PdfName.ENCODEDBYTEALIGN);
if (bo != null)
byteAlign = bo.BooleanValue;
}
byte[] outBuf = new byte[(width + 7) / 8 * height];
TIFFFaxDecompressor decoder = new TIFFFaxDecompressor();
if (k == 0 || k > 0) {
int tiffT4Options = k > 0 ? TIFFConstants.GROUP3OPT_2DENCODING : 0;
tiffT4Options |= byteAlign ? TIFFConstants.GROUP3OPT_FILLBITS : 0;
decoder.SetOptions(1, TIFFConstants.COMPRESSION_CCITTFAX3, tiffT4Options, 0);
decoder.DecodeRaw(outBuf, b, width, height);
if (decoder.fails > 0) {
byte[] outBuf2 = new byte[(width + 7) / 8 * height];
int oldFails = decoder.fails;
decoder.SetOptions(1, TIFFConstants.COMPRESSION_CCITTRLE, tiffT4Options, 0);
decoder.DecodeRaw(outBuf2, b, width, height);
if (decoder.fails < oldFails) {
outBuf = outBuf2;
}
}
}
else {
TIFFFaxDecoder deca = new TIFFFaxDecoder(1, width, height);
deca.DecodeT6(outBuf, b, 0, height, 0);
}
if (!blackIs1) {
int len = outBuf.Length;
for (int t = 0; t < len; ++t) {
outBuf[t] ^= 0xff;
}
}
b = outBuf;
}
else if (PdfName.CRYPT.Equals(name)) {
}
else
throw new UnsupportedPdfException(MessageLocalization.GetComposedMessage("the.filter.1.is.not.supported", name));
}
return b;
}
public byte[] Decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) {
PdfNumber wn = (PdfNumber)PdfReader.GetPdfObjectRelease(streamDictionary.Get(PdfName.WIDTH));
PdfNumber hn = (PdfNumber)PdfReader.GetPdfObjectRelease(streamDictionary.Get(PdfName.HEIGHT));
if (wn == null || hn == null)
throw new UnsupportedPdfException(MessageLocalization.GetComposedMessage("filter.ccittfaxdecode.is.only.supported.for.images"));
int width = wn.IntValue;
int height = hn.IntValue;
PdfDictionary param = decodeParams is PdfDictionary ? (PdfDictionary)decodeParams : null;
int k = 0;
bool blackIs1 = false;
bool byteAlign = false;
if (param != null) {
PdfNumber kn = param.GetAsNumber(PdfName.K);
if (kn != null)
k = kn.IntValue;
PdfBoolean bo = param.GetAsBoolean(PdfName.BLACKIS1);
if (bo != null)
blackIs1 = bo.BooleanValue;
bo = param.GetAsBoolean(PdfName.ENCODEDBYTEALIGN);
if (bo != null)
byteAlign = bo.BooleanValue;
}
byte[] outBuf = new byte[(width + 7) / 8 * height];
TIFFFaxDecompressor decoder = new TIFFFaxDecompressor();
if (k == 0 || k > 0) {
int tiffT4Options = k > 0 ? TIFFConstants.GROUP3OPT_2DENCODING : 0;
tiffT4Options |= byteAlign ? TIFFConstants.GROUP3OPT_FILLBITS : 0;
decoder.SetOptions(1, TIFFConstants.COMPRESSION_CCITTFAX3, tiffT4Options, 0);
decoder.DecodeRaw(outBuf, b, width, height);
if (decoder.fails > 0) {
byte[] outBuf2 = new byte[(width + 7) / 8 * height];
int oldFails = decoder.fails;
decoder.SetOptions(1, TIFFConstants.COMPRESSION_CCITTRLE, tiffT4Options, 0);
decoder.DecodeRaw(outBuf2, b, width, height);
if (decoder.fails < oldFails) {
outBuf = outBuf2;
}
}
}
else {
TIFFFaxDecoder deca = new TIFFFaxDecoder(1, width, height);
deca.DecodeT6(outBuf, b, 0, height, 0);
}
if (!blackIs1) {
int len = outBuf.Length;
for (int t = 0; t < len; ++t) {
outBuf[t] ^= 0xff;
}
}
b = outBuf;
return b;
}
