| public Decode2D ( byte buffer, byte compData, int startX, int height, long tiffT4Options ) : void | ||
| buffer | byte | |
| compData | byte | |
| startX | int | |
| height | int | |
| tiffT4Options | long | |
| return | void | |
public void Decode2D(byte[] buffer,
byte[] compData,
int startX,
int height,
long tiffT4Options) {
this.data = compData;
compression = 3;
bitPointer = 0;
bytePointer = 0;
int scanlineStride = (w + 7)/8;
int a0, a1, b1, b2;
int[] b = new int[2];
int entry, code, bits;
bool isWhite;
int currIndex = 0;
int[] temp;
// fillBits - dealt with this in readEOL
// 1D/2D encoding - dealt with this in readEOL
// uncompressedMode - haven't dealt with this yet.
oneD = (int)(tiffT4Options & 0x01);
uncompressedMode = (int)((tiffT4Options & 0x02) >> 1);
fillBits = (int)((tiffT4Options & 0x04) >> 2);
// The data must start with an EOL code
if (ReadEOL(true) != 1) {
throw new Exception("First scanline must be 1D encoded.");
}
int lineOffset = 0;
int bitOffset;
// Then the 1D encoded scanline data will occur, changing elements
// array gets set.
DecodeNextScanline(buffer, lineOffset, startX);
lineOffset += scanlineStride;
for (int lines = 1; lines < height; lines++) {
// Every line must begin with an EOL followed by a bit which
// indicates whether the following scanline is 1D or 2D encoded.
if (ReadEOL(false) == 0) {
// 2D encoded scanline follows
// Initialize previous scanlines changing elements, and
// initialize current scanline's changing elements array
temp = prevChangingElems;
prevChangingElems = currChangingElems;
currChangingElems = temp;
currIndex = 0;
// a0 has to be set just before the start of this scanline.
a0 = -1;
isWhite = true;
bitOffset = startX;
lastChangingElement = 0;
while (bitOffset < w) {
// Get the next changing element
GetNextChangingElement(a0, isWhite, b);
b1 = b[0];
b2 = b[1];
// Get the next seven bits
entry = NextLesserThan8Bits(7);
// Run these through the 2DCodes table
entry = (int)(twoDCodes[entry] & 0xff);
// Get the code and the number of bits used up
code = (entry & 0x78) >> 3;
bits = entry & 0x07;
if (code == 0) {
if (!isWhite) {
SetToBlack(buffer, lineOffset, bitOffset,
b2 - bitOffset);
}
bitOffset = a0 = b2;
// Set pointer to consume the correct number of bits.
UpdatePointer(7 - bits);
} else if (code == 1) {
// Horizontal
UpdatePointer(7 - bits);
// identify the next 2 codes.
int number;
if (isWhite) {
number = DecodeWhiteCodeWord();
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
number = DecodeBlackCodeWord();
SetToBlack(buffer, lineOffset, bitOffset, number);
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
} else {
number = DecodeBlackCodeWord();
SetToBlack(buffer, lineOffset, bitOffset, number);
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
number = DecodeWhiteCodeWord();
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
}
a0 = bitOffset;
} else if (code <= 8) {
// Vertical
a1 = b1 + (code - 5);
currChangingElems[currIndex++] = a1;
// We write the current color till a1 - 1 pos,
// since a1 is where the next color starts
if (!isWhite) {
SetToBlack(buffer, lineOffset, bitOffset,
a1 - bitOffset);
}
bitOffset = a0 = a1;
isWhite = !isWhite;
UpdatePointer(7 - bits);
} else {
throw new Exception("Invalid code encountered while decoding 2D group 3 compressed data.");
}
}
// Add the changing element beyond the current scanline for the
// other color too
currChangingElems[currIndex++] = bitOffset;
changingElemSize = currIndex;
} else {
// 1D encoded scanline follows
DecodeNextScanline(buffer, lineOffset, startX);
}
lineOffset += scanlineStride;
}
}
/** Reads a page from a TIFF image.
* @param s the file source
* @param page the page to get. The first page is 1
* @param direct for single strip, CCITT images, generate the image
* by direct byte copying. It's faster but may not work
* every time
* @return the <CODE>Image</CODE>
*/
public static Image GetTiffImage(RandomAccessFileOrArray s, int page, bool direct)
{
if (page < 1)
throw new ArgumentException(MessageLocalization.GetComposedMessage("the.page.number.must.be.gt.eq.1"));
TIFFDirectory dir = new TIFFDirectory(s, page - 1);
if (dir.IsTagPresent(TIFFConstants.TIFFTAG_TILEWIDTH))
throw new ArgumentException(MessageLocalization.GetComposedMessage("tiles.are.not.supported"));
int compression = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_COMPRESSION);
switch (compression) {
case TIFFConstants.COMPRESSION_CCITTRLEW:
case TIFFConstants.COMPRESSION_CCITTRLE:
case TIFFConstants.COMPRESSION_CCITTFAX3:
case TIFFConstants.COMPRESSION_CCITTFAX4:
break;
default:
return GetTiffImageColor(dir, s);
}
float rotation = 0;
if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ORIENTATION)) {
int rot = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_ORIENTATION);
if (rot == TIFFConstants.ORIENTATION_BOTRIGHT || rot == TIFFConstants.ORIENTATION_BOTLEFT)
rotation = (float)Math.PI;
else if (rot == TIFFConstants.ORIENTATION_LEFTTOP || rot == TIFFConstants.ORIENTATION_LEFTBOT)
rotation = (float)(Math.PI / 2.0);
else if (rot == TIFFConstants.ORIENTATION_RIGHTTOP || rot == TIFFConstants.ORIENTATION_RIGHTBOT)
rotation = -(float)(Math.PI / 2.0);
}
Image img = null;
long tiffT4Options = 0;
long tiffT6Options = 0;
int fillOrder = 1;
int h = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_IMAGELENGTH);
int w = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_IMAGEWIDTH);
int dpiX = 0;
int dpiY = 0;
float XYRatio = 0;
int resolutionUnit = TIFFConstants.RESUNIT_INCH;
if (dir.IsTagPresent(TIFFConstants.TIFFTAG_RESOLUTIONUNIT))
resolutionUnit = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_RESOLUTIONUNIT);
dpiX = GetDpi(dir.GetField(TIFFConstants.TIFFTAG_XRESOLUTION), resolutionUnit);
dpiY = GetDpi(dir.GetField(TIFFConstants.TIFFTAG_YRESOLUTION), resolutionUnit);
if (resolutionUnit == TIFFConstants.RESUNIT_NONE) {
if (dpiY != 0)
XYRatio = (float)dpiX / (float)dpiY;
dpiX = 0;
dpiY = 0;
}
int rowsStrip = h;
if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ROWSPERSTRIP))
rowsStrip = (int)dir.GetFieldAsLong(TIFFConstants.TIFFTAG_ROWSPERSTRIP);
if (rowsStrip <= 0 || rowsStrip > h)
rowsStrip = h;
long[] offset = GetArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPOFFSETS);
long[] size = GetArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPBYTECOUNTS);
if ((size == null || (size.Length == 1 && (size[0] == 0 || size[0] + offset[0] > s.Length))) && h == rowsStrip) { // some TIFF producers are really lousy, so...
size = new long[]{s.Length - (int)offset[0]};
}
bool reverse = false;
TIFFField fillOrderField = dir.GetField(TIFFConstants.TIFFTAG_FILLORDER);
if (fillOrderField != null)
fillOrder = fillOrderField.GetAsInt(0);
reverse = (fillOrder == TIFFConstants.FILLORDER_LSB2MSB);
int paramsn = 0;
if (dir.IsTagPresent(TIFFConstants.TIFFTAG_PHOTOMETRIC)) {
long photo = dir.GetFieldAsLong(TIFFConstants.TIFFTAG_PHOTOMETRIC);
if (photo == TIFFConstants.PHOTOMETRIC_MINISBLACK)
paramsn |= Image.CCITT_BLACKIS1;
}
int imagecomp = 0;
switch (compression) {
case TIFFConstants.COMPRESSION_CCITTRLEW:
case TIFFConstants.COMPRESSION_CCITTRLE:
imagecomp = Image.CCITTG3_1D;
paramsn |= Image.CCITT_ENCODEDBYTEALIGN | Image.CCITT_ENDOFBLOCK;
break;
case TIFFConstants.COMPRESSION_CCITTFAX3:
imagecomp = Image.CCITTG3_1D;
paramsn |= Image.CCITT_ENDOFLINE | Image.CCITT_ENDOFBLOCK;
TIFFField t4OptionsField = dir.GetField(TIFFConstants.TIFFTAG_GROUP3OPTIONS);
if (t4OptionsField != null) {
tiffT4Options = t4OptionsField.GetAsLong(0);
if ((tiffT4Options & TIFFConstants.GROUP3OPT_2DENCODING) != 0)
imagecomp = Image.CCITTG3_2D;
if ((tiffT4Options & TIFFConstants.GROUP3OPT_FILLBITS) != 0)
paramsn |= Image.CCITT_ENCODEDBYTEALIGN;
}
break;
case TIFFConstants.COMPRESSION_CCITTFAX4:
imagecomp = Image.CCITTG4;
TIFFField t6OptionsField = dir.GetField(TIFFConstants.TIFFTAG_GROUP4OPTIONS);
if (t6OptionsField != null)
tiffT6Options = t6OptionsField.GetAsLong(0);
break;
}
if (direct && rowsStrip == h) { //single strip, direct
byte[] im = new byte[(int)size[0]];
s.Seek(offset[0]);
s.ReadFully(im);
img = Image.GetInstance(w, h, false, imagecomp, paramsn, im);
img.Inverted = true;
}
else {
int rowsLeft = h;
CCITTG4Encoder g4 = new CCITTG4Encoder(w);
for (int k = 0; k < offset.Length; ++k) {
byte[] im = new byte[(int)size[k]];
s.Seek(offset[k]);
s.ReadFully(im);
int height = Math.Min(rowsStrip, rowsLeft);
TIFFFaxDecoder decoder = new TIFFFaxDecoder(fillOrder, w, height);
byte[] outBuf = new byte[(w + 7) / 8 * height];
switch (compression) {
case TIFFConstants.COMPRESSION_CCITTRLEW:
case TIFFConstants.COMPRESSION_CCITTRLE:
decoder.Decode1D(outBuf, im, 0, height);
g4.Fax4Encode(outBuf, height);
break;
case TIFFConstants.COMPRESSION_CCITTFAX3:
try {
decoder.Decode2D(outBuf, im, 0, height, tiffT4Options);
}
catch (Exception e) {
// let's flip the fill bits and try again...
tiffT4Options ^= TIFFConstants.GROUP3OPT_FILLBITS;
try {
decoder.Decode2D(outBuf, im, 0, height, tiffT4Options);
}
catch {
throw e;
}
}
g4.Fax4Encode(outBuf, height);
break;
case TIFFConstants.COMPRESSION_CCITTFAX4:
decoder.DecodeT6(outBuf, im, 0, height, tiffT6Options);
g4.Fax4Encode(outBuf, height);
break;
}
rowsLeft -= rowsStrip;
}
byte[] g4pic = g4.Close();
img = Image.GetInstance(w, h, false, Image.CCITTG4, paramsn & Image.CCITT_BLACKIS1, g4pic);
}
img.SetDpi(dpiX, dpiY);
img.XYRatio = XYRatio;
if (dir.IsTagPresent(TIFFConstants.TIFFTAG_ICCPROFILE)) {
try {
TIFFField fd = dir.GetField(TIFFConstants.TIFFTAG_ICCPROFILE);
ICC_Profile icc_prof = ICC_Profile.GetInstance(fd.GetAsBytes());
if (icc_prof.NumComponents == 1)
img.TagICC = icc_prof;
}
catch {
//empty
}
}
img.OriginalType = Image.ORIGINAL_TIFF;
if (rotation != 0)
img.InitialRotation = rotation;
return img;
}
