jpegmetadata.java

java1.6众多例子参考

/*
 * @(#)JPEGMetadata.java	1.30 07/11/26
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.imageio.plugins.jpeg;

import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageWriteParam;
import javax.imageio.IIOException;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.metadata.IIOMetadataNode;
import javax.imageio.metadata.IIOMetadataFormat;
import javax.imageio.metadata.IIOMetadataFormatImpl;
import javax.imageio.metadata.IIOInvalidTreeException;
import javax.imageio.plugins.jpeg.JPEGQTable;
import javax.imageio.plugins.jpeg.JPEGHuffmanTable;
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.NamedNodeMap;

import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.ListIterator;
import java.io.IOException;
import java.awt.color.ICC_Profile;
import java.awt.color.ICC_ColorSpace;
import java.awt.color.ColorSpace;
import java.awt.image.ColorModel;
import java.awt.Point;

/**
 * Metadata for the JPEG plug-in.
 */
public class JPEGMetadata extends IIOMetadata implements Cloneable {

    //////// Private variables

    private static final boolean debug = false;

    /**
     * A copy of <code>markerSequence</code>, created the first time the
     * <code>markerSequence</code> is modified.  This is used by reset
     * to restore the original state.
     */
    private List resetSequence = null;

    /**
     * Set to <code>true</code> when reading a thumbnail stored as 
     * JPEG.  This is used to enforce the prohibition of JFIF thumbnails
     * containing any JFIF marker segments, and to ensure generation of
     * a correct native subtree during <code>getAsTree</code>.
     */
    private boolean inThumb = false;

    /**
     * Set by the chroma node construction method to signal the
     * presence or absence of an alpha channel to the transparency
     * node construction method.  Used only when constructing a
     * standard metadata tree.
     */
    private boolean hasAlpha;

    //////// end of private variables

    /////// Package-access variables

    /**
     * All data is a list of <code>MarkerSegment</code> objects.
     * When accessing the list, use the tag to identify the particular
     * subclass.  Any JFIF marker segment must be the first element
     * of the list if it is present, and any JFXX or APP2ICC marker
     * segments are subordinate to the JFIF marker segment.  This
     * list is package visible so that the writer can access it.
     * @see #MarkerSegment
     */
    List markerSequence = new ArrayList();

    /**
     * Indicates whether this object represents stream or image
     * metadata.  Package-visible so the writer can see it.
     */
    final boolean isStream;

    /////// End of package-access variables

    /////// Constructors

    /**
     * Constructor containing code shared by other constructors.
     */
    JPEGMetadata(boolean isStream, boolean inThumb) {
        super(true,  // Supports standard format
              JPEG.nativeImageMetadataFormatName,  // and a native format
              JPEG.nativeImageMetadataFormatClassName,
              null, null);  // No other formats
        this.inThumb = inThumb;
        // But if we are stream metadata, adjust the variables
        this.isStream = isStream;
        if (isStream) {
            nativeMetadataFormatName = JPEG.nativeStreamMetadataFormatName;
            nativeMetadataFormatClassName = 
                JPEG.nativeStreamMetadataFormatClassName;
        }
    }

    /*
     * Constructs a <code>JPEGMetadata</code> object by reading the
     * contents of an <code>ImageInputStream</code>.  Has package-only
     * access.
     * 
     * @param isStream A boolean indicating whether this object will be
     * stream or image metadata.
     * @param isThumb A boolean indicating whether this metadata object
     * is for an image or for a thumbnail stored as JPEG.
     * @param iis An <code>ImageInputStream</code> from which to read
     * the metadata.
     * @param reader The <code>JPEGImageReader</code> calling this
     * constructor, to which warnings should be sent.
     */
    JPEGMetadata(boolean isStream,
                 boolean isThumb,
                 ImageInputStream iis, 
                 JPEGImageReader reader) throws IOException { 
        this(isStream, isThumb);

        JPEGBuffer buffer = new JPEGBuffer(iis);

        buffer.loadBuf(0);

        // The first three bytes should be FF, SOI, FF
        if (((buffer.buf[0] & 0xff) != 0xff) 
            || ((buffer.buf[1] & 0xff) != JPEG.SOI)
            || ((buffer.buf[2] & 0xff) != 0xff)) {
            throw new IIOException ("Image format error");
        }

        boolean done = false;
        buffer.bufAvail -=2;  // Next byte should be the ff before a marker
        buffer.bufPtr = 2;
        MarkerSegment newGuy = null;
        while (!done) {
            byte [] buf;
            int ptr;
            buffer.loadBuf(1);
            if (debug) {
                System.out.println("top of loop");
                buffer.print(10);
            }
            buffer.scanForFF(reader);
            switch (buffer.buf[buffer.bufPtr] & 0xff) {
            case 0:
                if (debug) {
                    System.out.println("Skipping 0");
                }
                buffer.bufAvail--;
                buffer.bufPtr++;
                break;
            case JPEG.SOF0:
            case JPEG.SOF1:
            case JPEG.SOF2:
                if (isStream) {
                    throw new IIOException 
                        ("SOF not permitted in stream metadata");
                }
                newGuy = new SOFMarkerSegment(buffer);
                break;
            case JPEG.DQT:
                newGuy = new DQTMarkerSegment(buffer);
                break;
            case JPEG.DHT:
                newGuy = new DHTMarkerSegment(buffer);
                break;
            case JPEG.DRI:
                newGuy = new DRIMarkerSegment(buffer);
                break;
            case JPEG.APP0:
                // Either JFIF, JFXX, or unknown APP0
                buffer.loadBuf(8); // tag, length, id
                buf = buffer.buf;
                ptr = buffer.bufPtr;
                if ((buf[ptr+3] == 'J') 
                    && (buf[ptr+4] == 'F')
                    && (buf[ptr+5] == 'I')
                    && (buf[ptr+6] == 'F')
                    && (buf[ptr+7] == 0)) {
                    if (inThumb) {
                        reader.warningOccurred
                            (JPEGImageReader.WARNING_NO_JFIF_IN_THUMB);
                        // Leave newGuy null
                        // Read a dummy to skip the segment
                        JFIFMarkerSegment dummy = 
                            new JFIFMarkerSegment(buffer);
                    } else if (isStream) {
                        throw new IIOException 
                            ("JFIF not permitted in stream metadata");
                    } else if (markerSequence.isEmpty() == false) {
                        throw new IIOException
                            ("JFIF APP0 must be first marker after SOI");
                    } else {
                        newGuy = new JFIFMarkerSegment(buffer);
                    }
                } else if ((buf[ptr+3] == 'J') 
                           && (buf[ptr+4] == 'F')
                           && (buf[ptr+5] == 'X')
                           && (buf[ptr+6] == 'X')
                           && (buf[ptr+7] == 0)) {
                    if (isStream) {
                        throw new IIOException 
                            ("JFXX not permitted in stream metadata");
                    }
                    if (inThumb) {
                        throw new IIOException
                          ("JFXX markers not allowed in JFIF JPEG thumbnail");
                    }
                    JFIFMarkerSegment jfif = 
                        (JFIFMarkerSegment) findMarkerSegment
                               (JFIFMarkerSegment.class, true);
                    if (jfif == null) {
                        throw new IIOException 
                            ("JFXX encountered without prior JFIF!");
                    }
                    jfif.addJFXX(buffer, reader);
                    // newGuy remains null
                } else {
                    newGuy = new MarkerSegment(buffer);
                    newGuy.loadData(buffer);
                }
                break;
            case JPEG.APP2:
                // Either an ICC profile or unknown APP2
                buffer.loadBuf(15); // tag, length, id
                if ((buffer.buf[buffer.bufPtr+3] == 'I')
                    && (buffer.buf[buffer.bufPtr+4] == 'C')
                    && (buffer.buf[buffer.bufPtr+5] == 'C')
                    && (buffer.buf[buffer.bufPtr+6] == '_')
                    && (buffer.buf[buffer.bufPtr+7] == 'P')
                    && (buffer.buf[buffer.bufPtr+8] == 'R')
                    && (buffer.buf[buffer.bufPtr+9] == 'O')
                    && (buffer.buf[buffer.bufPtr+10] == 'F')
                    && (buffer.buf[buffer.bufPtr+11] == 'I')
                    && (buffer.buf[buffer.bufPtr+12] == 'L')
                    && (buffer.buf[buffer.bufPtr+13] == 'E')
                    && (buffer.buf[buffer.bufPtr+14] == 0)
                    ) {
                    if (isStream) {
                        throw new IIOException 
                            ("ICC profiles not permitted in stream metadata");
                    }

                    JFIFMarkerSegment jfif = 
                        (JFIFMarkerSegment) findMarkerSegment
                        (JFIFMarkerSegment.class, true);
                    if (jfif == null) {
                        throw new IIOException 
                            ("ICC APP2 encountered without prior JFIF!");
                    }
                    jfif.addICC(buffer);
                    // newGuy remains null
                } else {
                    newGuy = new MarkerSegment(buffer);
                    newGuy.loadData(buffer);
                }
                break;
            case JPEG.APP14:
                // Either Adobe or unknown APP14
                buffer.loadBuf(8); // tag, length, id
                if ((buffer.buf[buffer.bufPtr+3] == 'A')
                    && (buffer.buf[buffer.bufPtr+4] == 'd')
                    && (buffer.buf[buffer.bufPtr+5] == 'o')
                    && (buffer.buf[buffer.bufPtr+6] == 'b')
                    && (buffer.buf[buffer.bufPtr+7] == 'e')) {
                    if (isStream) {
                        throw new IIOException 
                      ("Adobe APP14 markers not permitted in stream metadata");
                    }
                    newGuy = new AdobeMarkerSegment(buffer);
                } else {
                    newGuy = new MarkerSegment(buffer);
                    newGuy.loadData(buffer);
                }

                break;
            case JPEG.COM:
                newGuy = new COMMarkerSegment(buffer);
                break;
            case JPEG.SOS:
                if (isStream) {
                    throw new IIOException 
                        ("SOS not permitted in stream metadata");
                }
                newGuy = new SOSMarkerSegment(buffer);
                break;
            case JPEG.RST0:
            case JPEG.RST1:
            case JPEG.RST2:
            case JPEG.RST3:
            case JPEG.RST4:
            case JPEG.RST5:
            case JPEG.RST6:
            case JPEG.RST7:
                if (debug) {
                    System.out.println("Restart Marker");
                }
                buffer.bufPtr++; // Just skip it
                buffer.bufAvail--;
                break;
            case JPEG.EOI:
                done = true;
                buffer.bufPtr++;
                buffer.bufAvail--;
                break;
            default:
                newGuy = new MarkerSegment(buffer);
                newGuy.loadData(buffer);
                newGuy.unknown = true;
                break;
            }
            if (newGuy != null) {
                markerSequence.add(newGuy);
                if (debug) {
                    newGuy.print();
                }
                newGuy = null;
            }
        }