This sample finds images in a PDF file and decodes any barcodes that are found.

ReadBarcodeFromPDF.java

/*
 * Copyright Datalogics, Inc. 2015
 */

package pdfjt.cookbook.forms;

import com.adobe.internal.io.ByteArrayByteWriter;
import com.adobe.internal.io.ByteReader;
import com.adobe.internal.io.InputStreamByteReader;
import com.adobe.pdfjt.core.types.ASName;
import com.adobe.pdfjt.pdf.document.PDFDocument;
import com.adobe.pdfjt.pdf.document.PDFOpenOptions;
import com.adobe.pdfjt.pdf.graphics.xobject.PDFXObjectImage;
import com.adobe.pdfjt.pdf.graphics.xobject.PDFXObjectImageWithLocation;
import com.adobe.pdfjt.pdf.graphics.xobject.PDFXObjectImageWithLocationMap;
import com.adobe.pdfjt.services.imageconversion.BufferedImageWrapper;
import com.adobe.pdfjt.services.imageconversion.ImageManager;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.Result;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.HybridBinarizer;

import java.awt.image.BufferedImage;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.Arrays;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;

/**
 * This sample finds images in a PDF file and decodes any barcodes that are
 * found.
 */
public class ReadBarcodeFromPDF {

    private static final String inputPDFPath = "http://dev.datalogics.com/cookbook/forms/";
    private static final List<String> fileNameList = Arrays.asList("ReadBarcodeImage_QRCode.pdf", "ReadBarcodeImage_DataMatrix.pdf",
            "ReadBarcodeImage_PDF417.pdf");

    public static void main(String[] args) throws Exception {
        /*
         * For speed, declare which formats we're actually expecting. Only these
         * three will be tried.
         */
        List<BarcodeFormat> formats = Arrays.asList(BarcodeFormat.QR_CODE, BarcodeFormat.DATA_MATRIX, BarcodeFormat.PDF_417);
        Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
        hints.put(DecodeHintType.POSSIBLE_FORMATS, formats);

        /*
         * There's nothing in the image but the barcode, and the barcode is
         * probably lined up straight
         */
        hints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);

        // Try harder to get a valid decode.
        hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);

        for (String fileName : fileNameList) {
            /*
             * Read in each PDF file
             */
            URLConnection connection = new URL(inputPDFPath + fileName).openConnection();
            connection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.95 Safari/537.11");
            connection.connect();
            InputStream fis = connection.getInputStream();        
            ByteReader byteReader = new InputStreamByteReader(fis);
            PDFDocument pdfDocument = PDFDocument.newInstance(byteReader, PDFOpenOptions.newInstance());            
            /*
             * Create a map of all of the images in the PDF Document then
             * iterate through them converting each into a BufferedImage
             */
            PDFXObjectImageWithLocationMap pdfXObjectMap = ImageManager.getPDFXObjectMap(pdfDocument);
            Iterator<ASName> keyIterator = pdfXObjectMap.keySet().iterator();
            while (keyIterator.hasNext()) {
                ASName key = keyIterator.next();
                /*
                 * Zebra Crossing requires a BufferedImage as input to the
                 * decoding process so we need to create one from each
                 * PDFXObjectImage using the ImageManager, a class that
                 * facilitates converting images between standard Java
                 * representations and that used by PDF.
                 */
                PDFXObjectImageWithLocation pdfXObjectImageWithLocation = pdfXObjectMap.get(key);
                PDFXObjectImage pdfXObjectImage = pdfXObjectImageWithLocation.getXImage();
                /*
                 * Only try to decode the image if it's grayscale; don't try with color images.
                 */
                if (pdfXObjectImage.getColorSpace().getName() == ASName.k_DeviceGray) {
                    ByteArrayByteWriter byteArrayByteWriter = new ByteArrayByteWriter();
                    BufferedImageWrapper bufferedImageWrapper = ImageManager.toBufferedImage(pdfXObjectImage, byteArrayByteWriter);
                    BufferedImage bufferedImage = bufferedImageWrapper.getBufferedImage();
                    /*
                     * Now that we have the BufferedImage, we can use the Zebra
                     * Crossing tools to decode the image.
                     */
                    LuminanceSource source = new BufferedImageLuminanceSource(bufferedImage);
                    BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
                    MultiFormatReader reader = new MultiFormatReader();
                    try {
                        Result result = reader.decode(bitmap, hints);
                        System.out.println(fileName + " - " + result.getBarcodeFormat() + " Found:");
                        System.out.println(result.getText());
                        System.out.println();
                    } catch (Exception e) {
                        /*
                         * The image probably wasn't a barcode or wasn't one of
                         * the three we tried to read
                         */
                    }
                }
            }
        }

    }

}