itextpdf.jar is a component in iText 5 Java library to provide core functionalities. iText Java library allows you to generate and manage PDF documents.

The Source Code files are provided at iText GitHub site.

You can compile it to generate your JAR file, using pom.xml as the build configuration file.

The source code of itextpdf-5.5.14.jar is provided below:

⏎ com/itextpdf/text/pdf/parser/InlineImageUtils.java

/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2020 iText Group NV
 * Authors: Bruno Lowagie, Kevin Day, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS
 *
 * This program 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 Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * a covered work must retain the producer line in every PDF that is created
 * or manipulated using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */
package com.itextpdf.text.pdf.parser;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import com.itextpdf.text.exceptions.UnsupportedPdfException;
import com.itextpdf.text.log.Logger;
import com.itextpdf.text.log.LoggerFactory;
import com.itextpdf.text.pdf.FilterHandlers;
import com.itextpdf.text.pdf.PRTokeniser;
import com.itextpdf.text.pdf.PdfArray;
import com.itextpdf.text.pdf.PdfContentParser;
import com.itextpdf.text.pdf.PdfDictionary;
import com.itextpdf.text.pdf.PdfName;
import com.itextpdf.text.pdf.PdfNumber;
import com.itextpdf.text.pdf.PdfObject;
import com.itextpdf.text.pdf.PdfReader;

/**
 * Utility methods to help with processing of inline images
 * @since 5.0.4
 */
public final class InlineImageUtils {
    private final static Logger LOGGER = LoggerFactory.getLogger(InlineImageUtils.class.getName());
    private InlineImageUtils(){}

    /**
     * Simple class in case users need to differentiate an exception from processing
     * inline images vs other exceptions 
     * @since 5.0.4
     */
    public static class InlineImageParseException extends IOException{

		private static final long serialVersionUID = 233760879000268548L;

		public InlineImageParseException(String message) {
            super(message);
        }

    }
    
    /**
     * Map between key abbreviations allowed in dictionary of inline images and their
     * equivalent image dictionary keys
     */
    private final static Map<PdfName, PdfName> inlineImageEntryAbbreviationMap;
    static { // static initializer
        inlineImageEntryAbbreviationMap = new HashMap<PdfName, PdfName>();

        // allowed entries - just pass these through
        inlineImageEntryAbbreviationMap.put(PdfName.BITSPERCOMPONENT, PdfName.BITSPERCOMPONENT);
        inlineImageEntryAbbreviationMap.put(PdfName.COLORSPACE, PdfName.COLORSPACE);
        inlineImageEntryAbbreviationMap.put(PdfName.DECODE, PdfName.DECODE);
        inlineImageEntryAbbreviationMap.put(PdfName.DECODEPARMS, PdfName.DECODEPARMS);
        inlineImageEntryAbbreviationMap.put(PdfName.FILTER, PdfName.FILTER);
        inlineImageEntryAbbreviationMap.put(PdfName.HEIGHT, PdfName.HEIGHT);
        inlineImageEntryAbbreviationMap.put(PdfName.IMAGEMASK, PdfName.IMAGEMASK);
        inlineImageEntryAbbreviationMap.put(PdfName.INTENT, PdfName.INTENT);
        inlineImageEntryAbbreviationMap.put(PdfName.INTERPOLATE, PdfName.INTERPOLATE);
        inlineImageEntryAbbreviationMap.put(PdfName.WIDTH, PdfName.WIDTH);

        // abbreviations - transform these to corresponding correct values
        inlineImageEntryAbbreviationMap.put(new PdfName("BPC"), PdfName.BITSPERCOMPONENT);
        inlineImageEntryAbbreviationMap.put(new PdfName("CS"), PdfName.COLORSPACE);
        inlineImageEntryAbbreviationMap.put(new PdfName("D"), PdfName.DECODE);
        inlineImageEntryAbbreviationMap.put(new PdfName("DP"), PdfName.DECODEPARMS);
        inlineImageEntryAbbreviationMap.put(new PdfName("F"), PdfName.FILTER);
        inlineImageEntryAbbreviationMap.put(new PdfName("H"), PdfName.HEIGHT);
        inlineImageEntryAbbreviationMap.put(new PdfName("IM"), PdfName.IMAGEMASK);
        inlineImageEntryAbbreviationMap.put(new PdfName("I"), PdfName.INTERPOLATE);
        inlineImageEntryAbbreviationMap.put(new PdfName("W"), PdfName.WIDTH);
    }
    
    /**
     * Map between value abbreviations allowed in dictionary of inline images for COLORSPACE
     */
    private static final Map<PdfName, PdfName> inlineImageColorSpaceAbbreviationMap;
    static {
        inlineImageColorSpaceAbbreviationMap = new HashMap<PdfName, PdfName>();
        
        inlineImageColorSpaceAbbreviationMap.put(new PdfName("G"), PdfName.DEVICEGRAY);
        inlineImageColorSpaceAbbreviationMap.put(new PdfName("RGB"), PdfName.DEVICERGB);
        inlineImageColorSpaceAbbreviationMap.put(new PdfName("CMYK"), PdfName.DEVICECMYK);
        inlineImageColorSpaceAbbreviationMap.put(new PdfName("I"), PdfName.INDEXED);
    }
    
    /**
     * Map between value abbreviations allowed in dictionary of inline images for FILTER
     */
    private static final Map<PdfName, PdfName> inlineImageFilterAbbreviationMap;
    static {
        inlineImageFilterAbbreviationMap = new HashMap<PdfName, PdfName>();
        
        inlineImageFilterAbbreviationMap.put(new PdfName("AHx"), PdfName.ASCIIHEXDECODE);
        inlineImageFilterAbbreviationMap.put(new PdfName("A85"), PdfName.ASCII85DECODE);
        inlineImageFilterAbbreviationMap.put(new PdfName("LZW"), PdfName.LZWDECODE);
        inlineImageFilterAbbreviationMap.put(new PdfName("Fl"), PdfName.FLATEDECODE);
        inlineImageFilterAbbreviationMap.put(new PdfName("RL"), PdfName.RUNLENGTHDECODE);
        inlineImageFilterAbbreviationMap.put(new PdfName("CCF"), PdfName.CCITTFAXDECODE);
        inlineImageFilterAbbreviationMap.put(new PdfName("DCT"), PdfName.DCTDECODE);
    }
    
    /**
     * Parses an inline image from the provided content parser.  The parser must be positioned immediately following the BI operator in the content stream.
     * The parser will be left with current position immediately following the EI operator that terminates the inline image
     * @param ps the content parser to use for reading the image. 
     * @param colorSpaceDic a color space dictionary 
     * @return the parsed image
     * @throws IOException if anything goes wring with the parsing
     * @throws InlineImageParseException if parsing of the inline image failed due to issues specific to inline image processing
     */
    public static InlineImageInfo parseInlineImage(PdfContentParser ps, PdfDictionary colorSpaceDic) throws IOException{
        PdfDictionary inlineImageDictionary = parseInlineImageDictionary(ps);
        byte[] samples = parseInlineImageSamples(inlineImageDictionary, colorSpaceDic, ps);
        return new InlineImageInfo(samples, inlineImageDictionary);
    }
    
    /**
     * Parses the next inline image dictionary from the parser.  The parser must be positioned immediately following the EI operator.
     * The parser will be left with position immediately following the whitespace character that follows the ID operator that ends the inline image dictionary.
     * @param ps the parser to extract the embedded image information from
     * @return the dictionary for the inline image, with any abbreviations converted to regular image dictionary keys and values
     * @throws IOException if the parse fails
     */
    private static PdfDictionary parseInlineImageDictionary(PdfContentParser ps) throws IOException{
        // by the time we get to here, we have already parsed the BI operator
        PdfDictionary dictionary = new PdfDictionary();
        
        for(PdfObject key = ps.readPRObject(); key != null && !"ID".equals(key.toString()); key = ps.readPRObject()){
            PdfObject value = ps.readPRObject();

            PdfName resolvedKey = inlineImageEntryAbbreviationMap.get(key);
            if (resolvedKey == null)
                resolvedKey = (PdfName)key;

            dictionary.put(resolvedKey, getAlternateValue(resolvedKey, value));
        }

        int ch = ps.getTokeniser().read();
        if (!PRTokeniser.isWhitespace(ch))
            throw new IOException("Unexpected character " + ch + " found after ID in inline image");
        
        return dictionary;
    }
    
    /**
     * Transforms value abbreviations into their corresponding real value 
     * @param key the key that the value is for
     * @param value the value that might be an abbreviation
     * @return if value is an allowed abbreviation for the key, the expanded value for that abbreviation.  Otherwise, value is returned without modification 
     */
    private static PdfObject getAlternateValue(PdfName key, PdfObject value){
        if (key == PdfName.FILTER){
            if (value instanceof PdfName){
                PdfName altValue = inlineImageFilterAbbreviationMap.get(value);
                if (altValue != null)
                    return altValue;
            } else if (value instanceof PdfArray){
                PdfArray array = ((PdfArray)value);
                PdfArray altArray = new PdfArray();
                int count = array.size();
                for(int i = 0; i < count; i++){
                    altArray.add(getAlternateValue(key, array.getPdfObject(i)));
                }
                return altArray;
            }
        } else if (key == PdfName.COLORSPACE){
            PdfName altValue = inlineImageColorSpaceAbbreviationMap.get(value);
            if (altValue != null)
                return altValue;
        }
        
        return value;
    }
    
    /**
     * @param colorSpaceName the name of the color space. If null, a bi-tonal (black and white) color space is assumed.
     * @return the components per pixel for the specified color space
     */
    private static int getComponentsPerPixel(PdfName colorSpaceName, PdfDictionary colorSpaceDic){
        if (colorSpaceName == null)
            return 1;
        if (colorSpaceName.equals(PdfName.DEVICEGRAY))
            return 1;
        if (colorSpaceName.equals(PdfName.DEVICERGB))
            return 3;
        if (colorSpaceName.equals(PdfName.DEVICECMYK))
            return 4;
        
        if (colorSpaceDic != null){
            PdfArray colorSpace = colorSpaceDic.getAsArray(colorSpaceName);
            if (colorSpace != null){
                if (PdfName.INDEXED.equals(colorSpace.getAsName(0))){
                    return 1;
                }
            }
            else {
            	PdfName tempName = colorSpaceDic.getAsName(colorSpaceName);
            	if (tempName != null) {
            		return getComponentsPerPixel(tempName, colorSpaceDic);
            	}
            }
        }
        
        throw new IllegalArgumentException("Unexpected color space " + colorSpaceName);
    }
    
    /**
     * Computes the number of unfiltered bytes that each row of the image will contain.
     * If the number of bytes results in a partial terminating byte, this number is rounded up
     * per the PDF specification
     * @param imageDictionary the dictionary of the inline image
     * @return the number of bytes per row of the image
     */
    private static int computeBytesPerRow(PdfDictionary imageDictionary, PdfDictionary colorSpaceDic){
        PdfNumber wObj = imageDictionary.getAsNumber(PdfName.WIDTH);
        PdfNumber bpcObj = imageDictionary.getAsNumber(PdfName.BITSPERCOMPONENT);
        int cpp = getComponentsPerPixel(imageDictionary.getAsName(PdfName.COLORSPACE), colorSpaceDic);
        
        int w = wObj.intValue();
        int bpc = bpcObj != null ? bpcObj.intValue() : 1;
        
        
        int bytesPerRow = (w * bpc * cpp + 7) / 8;
        
        return bytesPerRow;
    }
    
    /**
     * Parses the samples of the image from the underlying content parser, ignoring all filters.
     * The parser must be positioned immediately after the ID operator that ends the inline image's dictionary.
     * The parser will be left positioned immediately following the EI operator.
     * This is primarily useful if no filters have been applied. 
     * @param imageDictionary the dictionary of the inline image
     * @param ps the content parser
     * @return the samples of the image
     * @throws IOException if anything bad happens during parsing
     */
    private static byte[] parseUnfilteredSamples(PdfDictionary imageDictionary, PdfDictionary colorSpaceDic, PdfContentParser ps) throws IOException{
        // special case:  when no filter is specified, we just read the number of bits
        // per component, multiplied by the width and height.
        if (imageDictionary.contains(PdfName.FILTER))
            throw new IllegalArgumentException("Dictionary contains filters");
        
        PdfNumber h = imageDictionary.getAsNumber(PdfName.HEIGHT);

        int bytesToRead = computeBytesPerRow(imageDictionary, colorSpaceDic) * h.intValue();
        byte[] bytes = new byte[bytesToRead];
        PRTokeniser tokeniser = ps.getTokeniser();
        
        int shouldBeWhiteSpace = tokeniser.read(); // skip next character (which better be a whitespace character - I suppose we could check for this)
        // from the PDF spec:  Unless the image uses ASCIIHexDecode or ASCII85Decode as one of its filters, the ID operator shall be followed by a single white-space character, and the next character shall be interpreted as the first byte of image data.
        // unfortunately, we've seen some PDFs where there is no space following the ID, so we have to capture this case and handle it
        int startIndex = 0;
        if (!PRTokeniser.isWhitespace(shouldBeWhiteSpace) || shouldBeWhiteSpace == 0){ // tokeniser treats 0 as whitespace, but for our purposes, we shouldn't
            bytes[0] = (byte)shouldBeWhiteSpace;
            startIndex++;
        }
        for(int i = startIndex; i < bytesToRead; i++){
            int ch = tokeniser.read();
            if (ch == -1)
                throw new InlineImageParseException("End of content stream reached before end of image data");
            
            bytes[i] = (byte)ch;
        }
        PdfObject ei = ps.readPRObject();
        if (!ei.toString().equals("EI")) {
            // Some PDF producers seem to add another non-whitespace character after the image data.
            // Let's try to handle that case here.
            PdfObject ei2 = ps.readPRObject();
            if (!ei2.toString().equals("EI"))
                throw new InlineImageParseException("EI not found after end of image data");
        }
        return bytes;
    }
    
    /**
     * Parses the samples of the image from the underlying content parser, accounting for filters
     * The parser must be positioned immediately after the ID operator that ends the inline image's dictionary.
     * The parser will be left positioned immediately following the EI operator.
     * <b>Note:</b>This implementation does not actually apply the filters at this time
     * @param imageDictionary the dictionary of the inline image
     * @param ps the content parser
     * @return the samples of the image
     * @throws IOException if anything bad happens during parsing
     */
    private static byte[] parseInlineImageSamples(PdfDictionary imageDictionary, PdfDictionary colorSpaceDic, PdfContentParser ps) throws IOException{
        // by the time we get to here, we have already parsed the ID operator
        
        if (!imageDictionary.contains(PdfName.FILTER)){
            return parseUnfilteredSamples(imageDictionary, colorSpaceDic, ps);
        }
        
        
        // read all content until we reach an EI operator surrounded by whitespace.
        // The following algorithm has two potential issues: what if the image stream 
        // contains <ws>EI<ws> ?
        // Plus, there are some streams that don't have the <ws> before the EI operator
        // it sounds like we would have to actually decode the content stream, which
        // I'd rather avoid right now.
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ByteArrayOutputStream accumulated = new ByteArrayOutputStream();
        int ch;
        int found = 0;
        PRTokeniser tokeniser = ps.getTokeniser();
        
        while ((ch = tokeniser.read()) != -1){
            if (found == 0 && PRTokeniser.isWhitespace(ch)){
                found++;
                accumulated.write(ch);
            } else if (found == 1 && ch == 'E'){
                found++;
                accumulated.write(ch);
            } else if (found == 1 && PRTokeniser.isWhitespace(ch)){
                // this clause is needed if we have a white space character that is part of the image data
                // followed by a whitespace character that precedes the EI operator.  In this case, we need
                // to flush the first whitespace, then treat the current whitespace as the first potential
                // character for the end of stream check.  Note that we don't increment 'found' here.
                baos.write(accumulated.toByteArray());
                accumulated.reset();
                accumulated.write(ch);
            } else if (found == 2 && ch == 'I'){ 
                found++;
                accumulated.write(ch);
            } else if (found == 3 && PRTokeniser.isWhitespace(ch)){
            	byte[] tmp = baos.toByteArray();
            	if (inlineImageStreamBytesAreComplete(tmp, imageDictionary)){
            		return tmp;
            	}
                baos.write(accumulated.toByteArray());
                accumulated.reset();
                
                baos.write(ch);
                found = 0;

            } else {
                baos.write(accumulated.toByteArray());
                accumulated.reset();
                
                baos.write(ch);
                found = 0;
            }
        }
        throw new InlineImageParseException("Could not find image data or EI");
    }
    
    private static boolean inlineImageStreamBytesAreComplete(byte[] samples, PdfDictionary imageDictionary){
    	try{
    		PdfReader.decodeBytes(samples, imageDictionary, FilterHandlers.getDefaultFilterHandlers());
    		return true;
    	}
        catch (UnsupportedPdfException e){
            LOGGER.warn(e.getMessage());
            return true;
        }
        catch (IOException e){
    		return false;
        }
    }
}

⏎ com/itextpdf/text/pdf/parser/InlineImageUtils.java

Or download all of them as a single archive file:

File name: itextpdf-5.5.14-fyi.zip
File size: 2163839 bytes
Release date: 2009-10-09
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