/** 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);
}
