xtifffield.java

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package org.libtiff.jai.codec;

/*
 * XTIFF: eXtensible TIFF libraries for JAI.
 * 
 * The contents of this file are subject to the  JAVA ADVANCED IMAGING
 * SAMPLE INPUT-OUTPUT CODECS AND WIDGET HANDLING SOURCE CODE  License
 * Version 1.0 (the "License"); You may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.sun.com/software/imaging/JAI/index.html
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License. 
 *
 * The Original Code is JAVA ADVANCED IMAGING SAMPLE INPUT-OUTPUT CODECS
 * AND WIDGET HANDLING SOURCE CODE. 
 * The Initial Developer of the Original Code is: Sun Microsystems, Inc..
 * Portions created by: Niles Ritter 
 * are Copyright (C): Niles Ritter, GeoTIFF.org, 1999,2000.
 * All Rights Reserved.
 * Contributor(s): Niles Ritter
 */

/**
 * XTIFFField is class representing a field in a TIFF 6.0 Image File Directory.
 * Unlike the JAI <code>TIFFField</code> class, this one is serializable,
 * assuming the underlying data object is. Revision: Fix getAsLongs to support
 * arrays of Short.
 * 
 * @see javax.media.jai.operator.TIFFDescriptor
 * @see TIFFDirectory
 */

public class XTIFFField extends Object implements java.io.Serializable,
        Comparable {

    /** Flag for 8 bit unsigned integers. */
    public static final int TIFF_BYTE = 1;

    /** Flag for null-terminated ASCII strings. */
    public static final int TIFF_ASCII = 2;

    /** Flag for 16 bit unsigned integers. */
    public static final int TIFF_SHORT = 3;

    /** Flag for 32 bit unsigned integers. */
    public static final int TIFF_LONG = 4;

    /** Flag for pairs of 32 bit unsigned integers. */
    public static final int TIFF_RATIONAL = 5;

    /** Flag for 8 bit signed integers. */
    public static final int TIFF_SBYTE = 6;

    /** Flag for 8 bit uninterpreted bytes. */
    public static final int TIFF_UNDEFINED = 7;

    /** Flag for 16 bit signed integers. */
    public static final int TIFF_SSHORT = 8;

    /** Flag for 32 bit signed integers. */
    public static final int TIFF_SLONG = 9;

    /** Flag for pairs of 32 bit signed integers. */
    public static final int TIFF_SRATIONAL = 10;

    /** Flag for 32 bit IEEE floats. */
    public static final int TIFF_FLOAT = 11;

    /** Flag for 64 bit IEEE doubles. */
    public static final int TIFF_DOUBLE = 12;

    /** The tag number. */
    int tag = 0;

    /** The tag type. */
    int type;

    /** The number of data items present in the field. */
    int count;

    /** The field data. (NB must be serializble!) */
    Object data;

    /** The default constructor. Made public for Serialization */
    public XTIFFField() {}

    /**
     * Constructs a XTIFFField with arbitrary data. The data parameter must be
     * an array of a Java type appropriate for the type of the TIFF field. Since
     * there is no available 32-bit unsigned datatype, long is used. The mapping
     * between types is as follows:
     * 
     * <table border=1>
     * <tr>
     * <th> TIFF type </th>
     * <th> Java type </th>
     * <tr>
     * <td><tt>TIFF_BYTE</tt></td>
     * <td><tt>byte</tt></td>
     * <tr>
     * <td><tt>TIFF_ASCII</tt></td>
     * <td><tt>String</tt></td>
     * <tr>
     * <td><tt>TIFF_SHORT</tt></td>
     * <td><tt>char</tt></td>
     * <tr>
     * <td><tt>TIFF_LONG</tt></td>
     * <td><tt>long</tt></td>
     * <tr>
     * <td><tt>TIFF_RATIONAL</tt></td>
     * <td><tt>long[2]</tt></td>
     * <tr>
     * <td><tt>TIFF_SBYTE</tt></td>
     * <td><tt>byte</tt></td>
     * <tr>
     * <td><tt>TIFF_UNDEFINED</tt></td>
     * <td><tt>byte</tt></td>
     * <tr>
     * <td><tt>TIFF_SSHORT</tt></td>
     * <td><tt>short</tt></td>
     * <tr>
     * <td><tt>TIFF_SLONG</tt></td>
     * <td><tt>int</tt></td>
     * <tr>
     * <td><tt>TIFF_SRATIONAL</tt></td>
     * <td><tt>int[2]</tt></td>
     * <tr>
     * <td><tt>TIFF_FLOAT</tt></td>
     * <td><tt>float</tt></td>
     * <tr>
     * <td><tt>TIFF_DOUBLE</tt></td>
     * <td><tt>double</tt></td>
     * </table>
     */
    public XTIFFField(int tag, int type, int count, Object data) {
        this.tag = tag;
        this.type = type;
        this.count = count;
        this.data = data;
    }

    /**
     * Returns the tag number, between 0 and 65535.
     */
    public int getTag() {
        return tag;
    }

    /**
     * Returns the type of the data stored in the IFD. For a TIFF6.0 file, the
     * value will equal one of the TIFF_ constants defined in this class. For
     * future revisions of TIFF, higher values are possible.
     * 
     */
    public int getType() {
        return type;
    }

    /**
     * Returns the number of elements in the IFD. (Image File Directory)
     * 
     * @see XTIFFDirectory
     */
    public int getCount() {
        return count;
    }

    /**
     * Returns the data as an uninterpreted array of bytes. The type of the
     * field must be one of TIFF_BYTE, TIFF_SBYTE, or TIFF_UNDEFINED;
     * 
     * <p>
     * For data in TIFF_BYTE format, the application must take care when
     * promoting the data to longer integral types to avoid sign extension.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_BYTE, TIFF_SBYTE, or TIFF_UNDEFINED.
     */
    public byte[] getAsBytes() {
        return (byte[]) data;
    }

    /**
     * Returns the data as an array of Strings. The type of the field must be
     * TIFF_ASCII.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_ASCII
     */
    public String[] getAsStrings() {
        return (String[]) data;
    }

    /**
     * Returns TIFF_SHORT data as an array of chars (unsigned 16-bit integers).
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_SHORT.
     */
    public char[] getAsChars() {
        return (char[]) data;
    }

    /**
     * Returns TIFF_SSHORT data as an array of shorts (signed 16-bit integers).
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_SSHORT.
     */
    public short[] getAsShorts() {
        return (short[]) data;
    }

    /**
     * Returns TIFF_SLONG data as an array of ints (signed 32-bit integers).
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_SLONG.
     */
    public int[] getAsInts() {
        return (int[]) data;
    }

    /**
     * Returns TIFF_LONG data as an array of longs (signed 64-bit integers).
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not an array of type
     * TIFF_LONG or TIFF_SHORT.
     */
    public long[] getAsLongs() {
        if (type == TIFF_SHORT) {
            char[] vals = (char[]) data;
            long[] newvals = new long[vals.length];
            for (int i = 0; i < vals.length; i++)
                newvals[i] = vals[i] & 0xffff;
            return newvals;
        } else {
            return (long[]) data;
        }
    }

    /**
     * Returns TIFF_FLOAT data as an array of floats.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_FLOAT.
     */
    public float[] getAsFloats() {
        return (float[]) data;
    }

    /**
     * Returns TIFF_DOUBLE data as an array of doubles.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_DOUBLE.
     */
    public double[] getAsDoubles() {
        return (double[]) data;
    }

    /**
     * Returns TIFF_SRATIONAL data as an array of 2-element arrays of ints.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_SRATIONAL.
     */
    public int[][] getAsSRationals() {
        return (int[][]) data;
    }

    /**
     * Returns TIFF_RATIONAL data as an array of 2-element arrays of longs.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_RATTIONAL.
     */
    public long[][] getAsRationals() {
        return (long[][]) data;
    }

    /**
     * Returns data in TIFF_BYTE, TIFF_SBYTE, TIFF_UNDEFINED, TIFF_SHORT,
     * TIFF_SSHORT, or TIFF_SLONG format as an int.
     * 
     * <p>
     * TIFF_BYTE and TIFF_UNDEFINED data are treated as unsigned; that is, no
     * sign extension will take place and the returned value will be in the
     * range [0, 255]. TIFF_SBYTE data will be returned in the range [-128,
     * 127].
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_BYTE, TIFF_SBYTE, TIFF_UNDEFINED, TIFF_SHORT, TIFF_SSHORT, or
     * TIFF_SLONG.
     */
    public int getAsInt(int index) {
        switch (type) {
        case TIFF_BYTE:
        case TIFF_UNDEFINED:
            return ((byte[]) data)[index] & 0xff;
        case TIFF_SBYTE:
            return ((byte[]) data)[index];
        case TIFF_SHORT:
            return ((char[]) data)[index] & 0xffff;
        case TIFF_SSHORT:
            return ((short[]) data)[index];
        case TIFF_SLONG:
            return ((int[]) data)[index];
        default:
            throw new ClassCastException();
        }
    }

    /**
     * Returns data in TIFF_BYTE, TIFF_SBYTE, TIFF_UNDEFINED, TIFF_SHORT,
     * TIFF_SSHORT, TIFF_SLONG, or TIFF_LONG format as a long.
     * 
     * <p>
     * TIFF_BYTE and TIFF_UNDEFINED data are treated as unsigned; that is, no
     * sign extension will take place and the returned value will be in the
     * range [0, 255]. TIFF_SBYTE data will be returned in the range [-128,
     * 127].
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_BYTE, TIFF_SBYTE, TIFF_UNDEFINED, TIFF_SHORT, TIFF_SSHORT,
     * TIFF_SLONG, or TIFF_LONG.
     */
    public long getAsLong(int index) {
        switch (type) {
        case TIFF_BYTE:
        case TIFF_UNDEFINED:
            return ((byte[]) data)[index] & 0xff;
        case TIFF_SBYTE:
            return ((byte[]) data)[index];
        case TIFF_SHORT:
            return ((char[]) data)[index] & 0xffff;
        case TIFF_SSHORT:
            return ((short[]) data)[index];
        case TIFF_SLONG:
            return ((int[]) data)[index];
        case TIFF_LONG:
            return ((long[]) data)[index];
        default:
            throw new ClassCastException();
        }
    }

    /**
     * Returns data in any numerical format as a float. Data in TIFF_SRATIONAL
     * or TIFF_RATIONAL format are evaluated by dividing the numerator into the
     * denominator using double-precision arithmetic and then truncating to
     * single precision. Data in TIFF_SLONG, TIFF_LONG, or TIFF_DOUBLE format
     * may suffer from truncation.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is of type
     * TIFF_UNDEFINED or TIFF_ASCII.
     */
    public float getAsFloat(int index) {
        switch (type) {
        case TIFF_BYTE:
            return ((byte[]) data)[index] & 0xff;
        case TIFF_SBYTE:
            return ((byte[]) data)[index];
        case TIFF_SHORT:
            return ((char[]) data)[index] & 0xffff;
        case TIFF_SSHORT:
            return ((short[]) data)[index];
        case TIFF_SLONG:
            return ((int[]) data)[index];
        case TIFF_LONG:
            return ((long[]) data)[index];
        case TIFF_FLOAT:
            return ((float[]) data)[index];
        case TIFF_DOUBLE:
            return (float) ((double[]) data)[index];
        case TIFF_SRATIONAL:
            int[] ivalue = getAsSRational(index);
            return (float) ((double) ivalue[0] / ivalue[1]);
        case TIFF_RATIONAL:
            long[] lvalue = getAsRational(index);
            return (float) ((double) lvalue[0] / lvalue[1]);
        default:
            throw new ClassCastException();
        }
    }

    /**
     * Returns data in any numerical format as a float. Data in TIFF_SRATIONAL
     * or TIFF_RATIONAL format are evaluated by dividing the numerator into the
     * denominator using double-precision arithmetic.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is of type
     * TIFF_UNDEFINED or TIFF_ASCII.
     */
    public double getAsDouble(int index) {
        switch (type) {
        case TIFF_BYTE:
            return ((byte[]) data)[index] & 0xff;
        case TIFF_SBYTE:
            return ((byte[]) data)[index];
        case TIFF_SHORT:
            return ((char[]) data)[index] & 0xffff;
        case TIFF_SSHORT:
            return ((short[]) data)[index];
        case TIFF_SLONG:
            return ((int[]) data)[index];
        case TIFF_LONG:
            return ((long[]) data)[index];
        case TIFF_FLOAT:
            return ((float[]) data)[index];
        case TIFF_DOUBLE:
            return ((double[]) data)[index];
        case TIFF_SRATIONAL:
            int[] ivalue = getAsSRational(index);
            return (double) ivalue[0] / ivalue[1];
        case TIFF_RATIONAL:
            long[] lvalue = getAsRational(index);
            return (double) lvalue[0] / lvalue[1];
        default:
            throw new ClassCastException();
        }
    }

    /**
     * Returns a TIFF_ASCII data item as a String.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_ASCII.
     */
    public String getAsString(int index) {
        return ((String[]) data)[index];
    }

    /**
     * Returns a TIFF_SRATIONAL data item as a two-element array of ints.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_SRATIONAL.
     */
    public int[] getAsSRational(int index) {
        return ((int[][]) data)[index];
    }

    /**
     * Returns a TIFF_RATIONAL data item as a two-element array of ints.
     * 
     * <p>
     * A ClassCastException will be thrown if the field is not of type
     * TIFF_RATIONAL.
     */
    public long[] getAsRational(int index) {
        return ((long[][]) data)[index];
    }

    /**
     * For sorting, implement Comparable
     */
    public int compareTo(Object o) throws ClassCastException {
        if (!(o instanceof XTIFFField))
            throw new ClassCastException("comparator is not an XTIFFField");
        if (o == null)
            throw new NullPointerException("comparator");
        return tag - ((XTIFFField) o).tag;
    }
}