I have a raw fax file (G3/T.4 format) and need to convert it into a multi-page TIFF programmatically via Java. JAI has not been successful for me so far even if I think it should work. Tools from sFaxTools have been successful for converting my raw fax files into TIFF (Batch Fax2Tif or Faxsee), but I need to do this programmatically via Java. I think there should be a possibility using java advanced imaging, please check the code snipplet below:
private void writeTiff(byte[] buffer, OutputStream outStream) {
try {
//reading image from given buffer
RenderedImage rendImage = null;
TIFFDecodeParam decodeParams = new TIFFDecodeParam();
ByteArrayInputStream stream = new ByteArrayInputStream(buffer);
ImageDecoder decoder = ImageCodec.createImageDecoder("tiff", stream, decodeParams);
TIFFEncodeParam encodeParams = new TIFFEncodeParam();
int numPages = decoder.getNumPages();
for (int i = 0; i < numPages; i++) {
rendImage = decoder.decodeAsRenderedImage(i);
ImageEncoder encoder = ImageCodec.createImageEncoder("TIFF", outStream, encodeParams);
encoder.encode(rendImage);
}
} catch (Exception e) {
e.printStackTrace();
} catch (Error err) {
err.printStackTrace();
}
}
The problem is, that the reading section especially ImageDecoder decoder = ImageCodec.createImageDecoder("tiff", stream, decodeParams); should be replaced by some ImageDecoder implementation which internally uses a FaxDecoder for decoding a g3 raw fax file. There is a protected class TIFFFaxDecoder within the the jai package, is it possible and how to use this for my purpose? Any idea? Thanks
I don't think JAI supports reading G3/T.4 raw fax data directly. However, here's sample code you can modify and extend to suit your needs, implementing the idea outlined in the comments (originally posted as a Gist).
It does not decode the G3/T.4 data in any way, it simply wraps the raw fax data in a minimal TIFF container. This allows the data to be read as a normal TIFF later. It uses (my own) TwelveMonkeys ImageIO library to do so.
If you don't know the width/height of the fax files, you might be able to implement an algorithm to find them, by using the CCITTFaxDecoderStream, trying the different widths (columns) defined in the standard, and see how many whole lines you can read. If you got the numbers right, you should fully consume the stream.
import com.twelvemonkeys.imageio.metadata.AbstractEntry;
import com.twelvemonkeys.imageio.metadata.Entry;
import com.twelvemonkeys.imageio.metadata.exif.EXIFWriter;
import com.twelvemonkeys.imageio.metadata.exif.Rational;
import com.twelvemonkeys.imageio.metadata.exif.TIFF;
import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import java.io.*;
import java.util.ArrayList;
public class G3Test {
public static void main(String[] args) throws IOException {
File input = new File(args[0]);
File output = new File(args.length > 1 ? args[1] : input.getName().replace(".g3", ".tif"));
// ImageWidth = 1728, 2048, 2482. SHORT or LONG. These are the fixed page widths in pixels defined in CCITT Group 3.
int columns = 1728; // The default
int rows = 100; // Trial and error for sample file found at http://www.filesuffix.com/en/extension/fax
ArrayList<Entry> entries = new ArrayList<>();
// http://cool.conservation-us.org/bytopic/imaging/std/tiff-f.html
// Required Class F tags
entries.add(new TIFFEntry(TIFF.TAG_COMPRESSION, TIFF.TYPE_SHORT, 3)); // CCITT T.4
entries.add(new TIFFEntry(TIFF.TAG_FILL_ORDER, TIFF.TYPE_SHORT, 1)); // Left to right
entries.add(new TIFFEntry(TIFF.TAG_GROUP3OPTIONS, TIFF.TYPE_LONG, 0)); // No options set
entries.add(new TIFFEntry(TIFF.TAG_IMAGE_WIDTH, TIFF.TYPE_LONG, columns));
entries.add(new TIFFEntry(TIFF.TAG_IMAGE_HEIGHT, TIFF.TYPE_LONG, rows));
entries.add(new TIFFEntry(TIFF.TAG_SUBFILE_TYPE, TIFF.TYPE_LONG, 2)); // Page
entries.add(new TIFFEntry(TIFF.TAG_RESOLUTION_UNIT, TIFF.TYPE_SHORT, 2)); // Inches
entries.add(new TIFFEntry(TIFF.TAG_X_RESOLUTION, TIFF.TYPE_RATIONAL, new Rational(204))); // 204
entries.add(new TIFFEntry(TIFF.TAG_Y_RESOLUTION, TIFF.TYPE_RATIONAL, new Rational(98))); // 98, 196
// Required Bilevel (Class B) tags
entries.add(new TIFFEntry(TIFF.TAG_BITS_PER_SAMPLE, TIFF.TYPE_SHORT, 1)); // 1 bit/sample
entries.add(new TIFFEntry(TIFF.TAG_PHOTOMETRIC_INTERPRETATION, TIFF.TYPE_SHORT, 0)); // White is zero
entries.add(new TIFFEntry(TIFF.TAG_SOFTWARE, TIFF.TYPE_ASCII, "TwelveMonkeys FAX2TIFF 0.1 BETA ;-)"));
entries.add(new TIFFEntry(TIFF.TAG_ROWS_PER_STRIP, TIFF.TYPE_LONG, rows));
entries.add(new TIFFEntry(TIFF.TAG_SAMPLES_PER_PIXEL, TIFF.TYPE_SHORT, 1)); // 1 sample/pixel
entries.add(new TIFFEntry(TIFF.TAG_STRIP_BYTE_COUNTS, TIFF.TYPE_LONG, input.length()));
entries.add(new TIFFEntry(TIFF.TAG_STRIP_OFFSETS, TIFF.TYPE_LONG, -1)); // placeholder for now
// We now have all our entries, compute size of the entries, and make that the offset (we'll write the data right after).
EXIFWriter writer = new EXIFWriter();
long offset = 12 + writer.computeIFDSize(entries); // + 12 for TIFF magic (4), IFD0 pointer (4) and EOF (4)
entries.remove(entries.size() - 1);
entries.add(new TIFFEntry(TIFF.TAG_STRIP_OFFSETS, TIFF.TYPE_LONG, offset));
try (InputStream in = new FileInputStream(input)) {
try (ImageOutputStream out = ImageIO.createImageOutputStream(output)) {
// Write the TIFF IFD for the image data
writer.write(entries, out);
// Copy the already G3 compressed bytes verbatim to the output
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) >= 0) {
out.write(buffer, 0, read);
}
}
}
}
// API stupidity, should be fixed in later verisons (ie. contain a predefined TIFFEntry class)
static final class TIFFEntry extends AbstractEntry {
private final short type;
TIFFEntry(int identifier, short type, Object value) {
super(identifier, value);
this.type = type;
}
@Override
public String getTypeName() {
return TIFF.TYPE_NAMES[type];
}
}
}