pngimage.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

/*
 * Copyright 2003 by Paulo Soares.
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (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.mozilla.org/MPL/
 *
 * 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 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 *
 *
 * The original JAI codecs have the following license
 *
 * Copyright (c) 2001 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * -Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduct the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that Software is not designed,licensed or intended for use in
 * the design, construction, operation or maintenance of any nuclear facility.
 */

package com.lowagie.text.pdf.codec;

import java.awt.color.ICC_Profile;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;

import com.lowagie.text.ExceptionConverter;
import com.lowagie.text.Image;
import com.lowagie.text.ImgRaw;
import com.lowagie.text.Utilities;
import com.lowagie.text.pdf.ByteBuffer;
import com.lowagie.text.pdf.PdfArray;
import com.lowagie.text.pdf.PdfDictionary;
import com.lowagie.text.pdf.PdfLiteral;
import com.lowagie.text.pdf.PdfName;
import com.lowagie.text.pdf.PdfNumber;
import com.lowagie.text.pdf.PdfObject;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfString;

/** Reads a PNG image. All types of PNG can be read.
 * <p>
 * It is based in part in the JAI codec.
 *
 * @author  Paulo Soares ([e-mail])
 */
public class PngImage {
/** Some PNG specific values. */
    public static final int[] PNGID = {137, 80, 78, 71, 13, 10, 26, 10};
    
/** A PNG marker. */
    public static final String IHDR = "IHDR";
    
/** A PNG marker. */
    public static final String PLTE = "PLTE";
    
/** A PNG marker. */
    public static final String IDAT = "IDAT";
    
/** A PNG marker. */
    public static final String IEND = "IEND";
    
/** A PNG marker. */
    public static final String tRNS = "tRNS";
    
/** A PNG marker. */
    public static final String pHYs = "pHYs";
    
/** A PNG marker. */
    public static final String gAMA = "gAMA";
    
/** A PNG marker. */
    public static final String cHRM = "cHRM";
    
/** A PNG marker. */
    public static final String sRGB = "sRGB";
    
/** A PNG marker. */
    public static final String iCCP = "iCCP";
    
    private static final int TRANSFERSIZE = 4096;
    private static final int PNG_FILTER_NONE = 0;
    private static final int PNG_FILTER_SUB = 1;
    private static final int PNG_FILTER_UP = 2;
    private static final int PNG_FILTER_AVERAGE = 3;
    private static final int PNG_FILTER_PAETH = 4;
    private static final PdfName intents[] = {PdfName.PERCEPTUAL,
        PdfName.RELATIVECALORIMETRIC,PdfName.SATURATION,PdfName.ABSOLUTECALORIMETRIC};
    
    InputStream is;
    DataInputStream dataStream;
    int width;
    int height;
    int bitDepth;
    int colorType;
    int compressionMethod;
    int filterMethod;
    int interlaceMethod;
    PdfDictionary additional = new PdfDictionary();
    byte image[];
    byte smask[];
    byte trans[];
    NewByteArrayOutputStream idat = new NewByteArrayOutputStream();
    int dpiX;
    int dpiY;
    float XYRatio;
    boolean genBWMask;
    boolean palShades;
    int transRedGray = -1;
    int transGreen = -1;
    int transBlue = -1;
    int inputBands;
    int bytesPerPixel; // number of bytes per input pixel
    byte colorTable[];
    float gamma = 1f;
    boolean hasCHRM = false;
    float xW, yW, xR, yR, xG, yG, xB, yB;
    PdfName intent;
    ICC_Profile icc_profile;

    
    
    /** Creates a new instance of PngImage */
    PngImage(InputStream is) {
        this.is = is;
    }
    
    /** Reads a PNG from an url.
     * @param url the url
     * @throws IOException on error
     * @return the image
     */    
    public static Image getImage(URL url) throws IOException {
        InputStream is = null;
        try {
            is = url.openStream();
            Image img = getImage(is);
            img.setUrl(url);
            return img;
        }
        finally {
            if (is != null) {
                is.close();
            }
        }
    }
    
    /** Reads a PNG from a stream.
     * @param is the stream
     * @throws IOException on error
     * @return the image
     */    
    public static Image getImage(InputStream is) throws IOException {
        PngImage png = new PngImage(is);
        return png.getImage();
    }
    
    /** Reads a PNG from a file.
     * @param file the file
     * @throws IOException on error
     * @return the image
     */    
    public static Image getImage(String file) throws IOException {
        return getImage(Utilities.toURL(file));
    }
    
    /** Reads a PNG from a byte array.
     * @param data the byte array
     * @throws IOException on error
     * @return the image
     */    
    public static Image getImage(byte data[]) throws IOException {
        ByteArrayInputStream is = new ByteArrayInputStream(data);
        Image img = getImage(is);
        img.setOriginalData(data);
        return img;
    }
    
    boolean checkMarker(String s) {
        if (s.length() != 4)
            return false;
        for (int k = 0; k < 4; ++k) {
            char c = s.charAt(k);
            if ((c < 'a' || c > 'z') && (c < 'A' || c > 'Z'))
                return false;
        }
        return true;
    }
    
    void readPng() throws IOException {
        for (int i = 0; i < PNGID.length; i++) {
            if (PNGID[i] != is.read())	{
                throw new IOException("File is not a valid PNG.");
            }
        }
        byte buffer[] = new byte[TRANSFERSIZE];
        while (true) {
            int len = getInt(is);
            String marker = getString(is);
            if (len < 0 || !checkMarker(marker))
                throw new IOException("Corrupted PNG file.");
            if (IDAT.equals(marker)) {
                int size;
                while (len != 0) {
                    size = is.read(buffer, 0, Math.min(len, TRANSFERSIZE));
                    if (size < 0)
                        return;
                    idat.write(buffer, 0, size);
                    len -= size;
                }
            }
            else if (tRNS.equals(marker)) {
                switch (colorType) {
                    case 0:
                        if (len >= 2) {
                            len -= 2;
                            int gray = getWord(is);
                            if (bitDepth == 16)
                                transRedGray = gray;
                            else
                                additional.put(PdfName.MASK, new PdfLiteral("["+gray+" "+gray+"]"));
                        }
                        break;
                    case 2:
                        if (len >= 6) {
                            len -= 6;
                            int red = getWord(is);
                            int green = getWord(is);
                            int blue = getWord(is);
                            if (bitDepth == 16) {
                                transRedGray = red;
                                transGreen = green;
                                transBlue = blue;
                            }
                            else
                                additional.put(PdfName.MASK, new PdfLiteral("["+red+" "+red+" "+green+" "+green+" "+blue+" "+blue+"]"));
                        }
                        break;
                    case 3:
                        if (len > 0) {
                            trans = new byte[len];
                            for (int k = 0; k < len; ++k)
                                trans[k] = (byte)is.read();
                            len = 0;
                        }
                        break;
                }
                Utilities.skip(is, len);
            }
            else if (IHDR.equals(marker)) {
                width = getInt(is);
                height = getInt(is);
                
                bitDepth = is.read();
                colorType = is.read();
                compressionMethod = is.read();
                filterMethod = is.read();
                interlaceMethod = is.read();
            }
            else if (PLTE.equals(marker)) {