convertcolorspace.java

非常有用的操作pdf文件的java源码

/**
 * Copyright (c) 2006, www.pdfbox.org
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of pdfbox; nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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package org.pdfbox;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.pdfbox.cos.COSFloat;
import org.pdfbox.cos.COSNumber;
import org.pdfbox.exceptions.InvalidPasswordException;
import org.pdfbox.pdfparser.PDFStreamParser;
import org.pdfbox.pdfwriter.ContentStreamWriter;
import org.pdfbox.pdmodel.PDDocument;
import org.pdfbox.pdmodel.PDPage;
import org.pdfbox.pdmodel.common.PDStream;
import org.pdfbox.util.PDFOperator;

/**
 * This is the main program that simply parses the pdf document and replace 
 * change a PDF to use a specific colorspace.
 *
 * @author <a href="[e-mail]">Ben Litchfield</a>
 * @author Pierre-Yves Landuré ([e-mail])
 * @version $Revision: 1.5 $
 */
public class ConvertColorspace
{

    private static final String PASSWORD = "-password";
    private static final String CONVERSION = "-equiv";
    private static final String DEST_COLORSPACE = "-toColorspace";

    /**
     * private constructor.
    */
    private ConvertColorspace()
    {
        //static class
    }

    /**
     * The method that replace RGB colors by CMYK ones.
     *
     * @param inputFile input file name.
     * @param colorEquivalents a dictionnary for the color equivalents.
     * @param destColorspace The destination colorspace, currently CMYK is supported.
     *
     * @throws IOException If there is an error parsing the document.
     */
    private void replaceColors( PDDocument inputFile,
                               Hashtable colorEquivalents,
                               String destColorspace ) throws IOException
    {
        if( !destColorspace.equals( "CMYK" ) )
        {
            throw new IOException( "Error: Unknown colorspace " + destColorspace );
        }
        List pagesList =  inputFile.getDocumentCatalog().getAllPages();

        PDPage currentPage = null;
        PDFStreamParser parser = null;
        List pageTokens = null;
        List editedPageTokens = null;

        for(int pageCounter = 0; pageCounter < pagesList.size(); pageCounter++) // For each document page
        {
            currentPage = (PDPage)pagesList.get( pageCounter );

            parser = new PDFStreamParser(currentPage.getContents().getStream());
            parser.parse();
            pageTokens = parser.getTokens();
            editedPageTokens = new ArrayList();

            for( int counter = 0; counter < pageTokens.size(); counter++) // For each page token
            {
                Object token = pageTokens.get( counter );
                if( token instanceof PDFOperator ) // Test if PDFOperator
                {
                    PDFOperator tokenOperator = (PDFOperator)token;

                    if(tokenOperator.getOperation().equals("rg")) // Test if "rg" Operator.
                    {
                        if( destColorspace.equals( "CMYK" ) )
                        {
                            replaceRGBTokensWithCMYKTokens( editedPageTokens, pageTokens, counter, colorEquivalents );
                            editedPageTokens.add( PDFOperator.getOperator( "k" ));
                        }
                    }
                    else if(tokenOperator.getOperation().equals("RG")) // Test if "rg" Operator.
                    {
                        if( destColorspace.equals( "CMYK" ) )
                        {
                            replaceRGBTokensWithCMYKTokens( editedPageTokens, pageTokens, counter, colorEquivalents );
                            editedPageTokens.add( PDFOperator.getOperator( "K" ));
                        }
                    }
                    else if(tokenOperator.getOperation().equals("g")) // Test if "rg" Operator.
                    {
                        if( destColorspace.equals( "CMYK" ) )
                        {
                            replaceGrayTokensWithCMYKTokens( editedPageTokens, pageTokens, counter, colorEquivalents );
                            editedPageTokens.add( PDFOperator.getOperator( "k" ));
                        }
                    }
                    else if(tokenOperator.getOperation().equals("G")) // Test if "rg" Operator.
                    {
                        if( destColorspace.equals( "CMYK" ) )
                        {
                            replaceGrayTokensWithCMYKTokens( editedPageTokens, pageTokens, counter, colorEquivalents );
                            editedPageTokens.add( PDFOperator.getOperator( "K" ));
                        }
                    }
                    else
                    {
                        editedPageTokens.add( token );
                    }
                }
                else // Test if PDFOperator
                {
                    editedPageTokens.add( token );
                }
            } // For each page token

            // We replace original page content by the edited one.
            PDStream updatedPageContents = new PDStream(inputFile);
            ContentStreamWriter contentWriter = new ContentStreamWriter( updatedPageContents.createOutputStream() );
            contentWriter.writeTokens( editedPageTokens );
            currentPage.setContents( updatedPageContents );

        } // For each document page            
    }
    
    private void replaceRGBTokensWithCMYKTokens( List editedPageTokens, 
                                                 List pageTokens, 
                                                 int counter,
                                                 Hashtable colorEquivalents )
    {
//      Get current RGB color.
        float red = ((COSNumber)pageTokens.get( counter - 3 )).floatValue();
        float green = ((COSNumber)pageTokens.get( counter - 2 )).floatValue();
        float blue = ((COSNumber)pageTokens.get( counter - 1 )).floatValue();

        int intRed = Math.round(red * 255.0f);
        int intGreen = Math.round(green * 255.0f);
        int intBlue = Math.round(blue * 255.0f);
        
        ColorSpaceInstance rgbColor = new ColorSpaceInstance();
        rgbColor.colorspace = "RGB";
        rgbColor.colorspaceValues = new int[] { intRed, intGreen, intBlue };
        ColorSpaceInstance cmykColor = (ColorSpaceInstance)colorEquivalents.get(rgbColor);
        float[] cmyk = null;

        if( cmykColor != null )
        {
            cmyk = new float[] {
                cmykColor.colorspaceValues[0] / 100.0f,
                cmykColor.colorspaceValues[1] / 100.0f,
                cmykColor.colorspaceValues[2] / 100.0f,
                cmykColor.colorspaceValues[3] / 100.0f
            };
        }
        else
        {
            cmyk = convertRGBToCMYK( red, green, blue );
        }

        //remove the RGB components that are already part of the editedPageTokens list
        editedPageTokens.remove( editedPageTokens.size() -1 );
        editedPageTokens.remove( editedPageTokens.size() -1 );
        editedPageTokens.remove( editedPageTokens.size() -1 );

        // Add the new CMYK color
        editedPageTokens.add( new COSFloat( cmyk[0] ) );
        editedPageTokens.add( new COSFloat( cmyk[1] ) );
        editedPageTokens.add( new COSFloat( cmyk[2] ) );
        editedPageTokens.add( new COSFloat( cmyk[3] ) );
    }
    
    private void replaceGrayTokensWithCMYKTokens( List editedPageTokens, 
                                                  List pageTokens, 
                                                  int counter, 
                                                  Hashtable colorEquivalents )
    {
//      Get current RGB color.
        float gray = ((COSNumber)pageTokens.get( counter - 1 )).floatValue();
        
        ColorSpaceInstance grayColor = new ColorSpaceInstance();
        grayColor.colorspace = "Grayscale";
        grayColor.colorspaceValues = new int[] { Math.round( gray * 100 ) };
        ColorSpaceInstance cmykColor = (ColorSpaceInstance)colorEquivalents.get(grayColor);
        float[] cmyk = null;

        if( cmykColor != null )
        {
            cmyk = new float[] {
                cmykColor.colorspaceValues[0] / 100.0f,
                cmykColor.colorspaceValues[1] / 100.0f,
                cmykColor.colorspaceValues[2] / 100.0f,
                cmykColor.colorspaceValues[3] / 100.0f
            };
        }
        else
        {
            cmyk = new float[] {0,0,0,gray};
        }

        //remove the Gray components that are already part of the editedPageTokens list
        editedPageTokens.remove( editedPageTokens.size() -1 );

        // Add the new CMYK color