tiffimage.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
    }
    
    protected static Image getTiffImageColor(TIFFDirectory dir, RandomAccessFileOrArray s) {
        try {
            int compression = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_COMPRESSION);
            int predictor = 1;
            TIFFLZWDecoder lzwDecoder = null;
            switch (compression) {
                case TIFFConstants.COMPRESSION_NONE:
                case TIFFConstants.COMPRESSION_LZW:
                case TIFFConstants.COMPRESSION_PACKBITS:
                case TIFFConstants.COMPRESSION_DEFLATE:
                case TIFFConstants.COMPRESSION_OJPEG:
                case TIFFConstants.COMPRESSION_JPEG:
                    break;
                default:
                    throw new IllegalArgumentException("The compression " + compression + " is not supported.");
            }
            int photometric = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_PHOTOMETRIC);
            switch (photometric) {
                case TIFFConstants.PHOTOMETRIC_MINISWHITE:
                case TIFFConstants.PHOTOMETRIC_MINISBLACK:
                case TIFFConstants.PHOTOMETRIC_RGB:
                case TIFFConstants.PHOTOMETRIC_SEPARATED:
                case TIFFConstants.PHOTOMETRIC_PALETTE:
                    break;
                default:
                    if (compression != TIFFConstants.COMPRESSION_OJPEG && compression != TIFFConstants.COMPRESSION_JPEG)
                        throw new IllegalArgumentException("The photometric " + photometric + " is not supported.");
            }
            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);
            }
            if (dir.isTagPresent(TIFFConstants.TIFFTAG_PLANARCONFIG)
                && dir.getFieldAsLong(TIFFConstants.TIFFTAG_PLANARCONFIG) == TIFFConstants.PLANARCONFIG_SEPARATE)
                throw new IllegalArgumentException("Planar images are not supported.");
            if (dir.isTagPresent(TIFFConstants.TIFFTAG_EXTRASAMPLES))
                throw new IllegalArgumentException("Extra samples are not supported.");
            int samplePerPixel = 1;
            if (dir.isTagPresent(TIFFConstants.TIFFTAG_SAMPLESPERPIXEL)) // 1,3,4
                samplePerPixel = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_SAMPLESPERPIXEL);
            int bitsPerSample = 1;
            if (dir.isTagPresent(TIFFConstants.TIFFTAG_BITSPERSAMPLE))
                bitsPerSample = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_BITSPERSAMPLE);
            switch (bitsPerSample) {
                case 1:
                case 2:
                case 4:
                case 8:
                    break;
                default:
                    throw new IllegalArgumentException("Bits per sample " + bitsPerSample + " is not supported.");
            }
            Image img = null;

            int h = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_IMAGELENGTH);
            int w = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_IMAGEWIDTH);
            int dpiX = 0;
            int dpiY = 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);
            int rowsStrip = h;
            if (dir.isTagPresent(TIFFConstants.TIFFTAG_ROWSPERSTRIP)) //another hack for broken tiffs
                rowsStrip = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_ROWSPERSTRIP);
            long offset[] = getArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPOFFSETS);
            long size[] = getArrayLongShort(dir, TIFFConstants.TIFFTAG_STRIPBYTECOUNTS);
            if ((size == null || (size.length == 1 && size[0] == 0)) && h == rowsStrip) { // some TIFF producers are really lousy, so...
                size = new long[]{s.length() - (int)offset[0]};
            }
            if (compression == TIFFConstants.COMPRESSION_LZW) {
                TIFFField predictorField = dir.getField(TIFFConstants.TIFFTAG_PREDICTOR);
                if (predictorField != null) {
                    predictor = predictorField.getAsInt(0);
                    if (predictor != 1 && predictor != 2) {
                        throw new RuntimeException("Illegal value for Predictor in TIFF file."); 
                    }
                    if (predictor == 2 && bitsPerSample != 8) {
                        throw new RuntimeException(bitsPerSample + "-bit samples are not supported for Horizontal differencing Predictor.");
                    }
                }
                lzwDecoder = new TIFFLZWDecoder(w, predictor, 
                                                samplePerPixel); 
            }
            int rowsLeft = h;
            ByteArrayOutputStream stream = null;
            DeflaterOutputStream zip = null;
            CCITTG4Encoder g4 = null;
            if (bitsPerSample == 1 && samplePerPixel == 1) {
                g4 = new CCITTG4Encoder(w);
            }
            else {
                stream = new ByteArrayOutputStream();
                if (compression != TIFFConstants.COMPRESSION_OJPEG && compression != TIFFConstants.COMPRESSION_JPEG)
                    zip = new DeflaterOutputStream(stream);
            }
            if (compression == TIFFConstants.COMPRESSION_OJPEG) {
                if ((!dir.isTagPresent(TIFFConstants.TIFFTAG_JPEGIFOFFSET))
                || (!dir.isTagPresent(TIFFConstants.TIFFTAG_JPEGIFBYTECOUNT))) {
                    throw new RuntimeException("Missing tag(s) for OJPEG compression.");
                }
                int jpegOffset = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_JPEGIFOFFSET);
                int jpegLength = (int)dir.getFieldAsLong(TIFFConstants.TIFFTAG_JPEGIFBYTECOUNT) +
                        (int)size[0];

                byte[] jpeg = new byte[Math.min(jpegLength, s.length() - jpegOffset)];

                int posFilePointer = s.getFilePointer();
                posFilePointer += jpegOffset;
                s.seek(posFilePointer);
                s.readFully(jpeg);
                img = new Jpeg(jpeg);
            } 
            else if (compression == TIFFConstants.COMPRESSION_JPEG) {
                if (size.length > 1)
                    throw new IOException("Compression JPEG is only supported with a single strip. This image has " + size.length + " strips.");
                byte[] jpeg = new byte[(int)size[0]];
                s.seek(offset[0]);
                s.readFully(jpeg);
                img = new Jpeg(jpeg);
            } 
            else {
                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);
                    byte outBuf[] = null;
                    if (compression != TIFFConstants.COMPRESSION_NONE)
                        outBuf = new byte[(w * bitsPerSample * samplePerPixel + 7) / 8 * height];
                    switch (compression) {
                        case TIFFConstants.COMPRESSION_DEFLATE:
                            inflate(im, outBuf);
                            break;
                        case TIFFConstants.COMPRESSION_NONE:
                            outBuf = im;
                            break;
                        case TIFFConstants.COMPRESSION_PACKBITS:
                            decodePackbits(im,  outBuf);
                            break;
                        case TIFFConstants.COMPRESSION_LZW:
                            lzwDecoder.decode(im, outBuf, height);
                            break;
                    }
                    if (bitsPerSample == 1 && samplePerPixel == 1) {
                        g4.fax4Encode(outBuf, height);
                    }
                    else {
                        zip.write(outBuf);
                    }
                    rowsLeft -= rowsStrip;
                }
                if (bitsPerSample == 1 && samplePerPixel == 1) {
                    img = Image.getInstance(w, h, false, Image.CCITTG4, 
                        photometric == TIFFConstants.PHOTOMETRIC_MINISBLACK ? Image.CCITT_BLACKIS1 : 0, g4.close());
                }
                else {
                    zip.close();
                    img = Image.getInstance(w, h, samplePerPixel, bitsPerSample, stream.toByteArray());
                    img.setDeflated(true);
                }
            }
            img.setDpi(dpiX, dpiY);
            if (compression != TIFFConstants.COMPRESSION_OJPEG && compression != TIFFConstants.COMPRESSION_JPEG) {
                if (dir.isTagPresent(TIFFConstants.TIFFTAG_ICCPROFILE)) {
                    try {
                        TIFFField fd = dir.getField(TIFFConstants.TIFFTAG_ICCPROFILE);
                        ICC_Profile icc_prof = ICC_Profile.getInstance(fd.getAsBytes());
                        if (samplePerPixel == icc_prof.getNumComponents())
                            img.tagICC(icc_prof);
                    }
                    catch (RuntimeException e) {
                        //empty
                    }
                }
                if (dir.isTagPresent(TIFFConstants.TIFFTAG_COLORMAP)) {
                    TIFFField fd = dir.getField(TIFFConstants.TIFFTAG_COLORMAP);
                    char rgb[] = fd.getAsChars();
                    byte palette[] = new byte[rgb.length];
                    int gColor = rgb.length / 3;
                    int bColor = gColor * 2;
                    for (int k = 0; k < gColor; ++k) {
                        palette[k * 3] = (byte)(rgb[k] >>> 8);
                        palette[k * 3 + 1] = (byte)(rgb[k + gColor] >>> 8);
                        palette[k * 3 + 2] = (byte)(rgb[k + bColor] >>> 8);
                    }
                    PdfArray indexed = new PdfArray();
                    indexed.add(PdfName.INDEXED);
                    indexed.add(PdfName.DEVICERGB);
                    indexed.add(new PdfNumber(gColor - 1));
                    indexed.add(new PdfString(palette));
                    PdfDictionary additional = new PdfDictionary();
                    additional.put(PdfName.COLORSPACE, indexed);
                    img.setAdditional(additional);
                }
                img.setOriginalType(Image.ORIGINAL_TIFF);
            }
            if (photometric == TIFFConstants.PHOTOMETRIC_MINISWHITE)
                img.setInverted(true);
            if (rotation != 0)
                img.setInitialRotation(rotation);
            return img;
        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
    }
    
    static long[] getArrayLongShort(TIFFDirectory dir, int tag) {
        TIFFField field = dir.getField(tag);
        if (field == null)
            return null;
        long offset[];
        if (field.getType() == TIFFField.TIFF_LONG)
            offset = field.getAsLongs();
        else { // must be short
            char temp[] = field.getAsChars();
            offset = new long[temp.length];
            for (int k = 0; k < temp.length; ++k)
                offset[k] = temp[k];
        }
        return offset;
    }
    
    // Uncompress packbits compressed image data.
    public static void decodePackbits(byte data[], byte[] dst) {
        int srcCount = 0, dstCount = 0;
        byte repeat, b;
        
        while (dstCount < dst.length) {
            b = data[srcCount++];
            if (b >= 0 && b <= 127) {
                // literal run packet
                for (int i=0; i<(b + 1); i++) {
                    dst[dstCount++] = data[srcCount++];
                }

            } else if (b <= -1 && b >= -127) {
                // 2 byte encoded run packet
                repeat = data[srcCount++];
                for (int i=0; i<(-b + 1); i++) {
                    dst[dstCount++] = repeat;
                }
            } else {
                // no-op packet. Do nothing
                srcCount++;
            }
        }
    }

    public static void inflate(byte[] deflated, byte[] inflated) {
        Inflater inflater = new Inflater();
        inflater.setInput(deflated);
        try {
            inflater.inflate(inflated);
        }
        catch(DataFormatException dfe) {
            throw new ExceptionConverter(dfe);
        }
    }

}