Images that use different filters

This is a code example of iText PDF, discover more.

31st May 2016
admin-marketing
FlateCompressJPEG1Pass.java
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/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2019 iText Group NV
    Authors: iText Software.
 
    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
/**
 * This sample is written by Bruno Lowagie in answer to the following question:
 * http://stackoverflow.com/questions/21958449/can-itextsharp-generate-pdf-with-jpeg-images-that-are-multi-stage-filtered-both
 * <p>
 * The question was about adding compression to an image that already used /DCTDecode
 * <p>
 * IMPORTANT:
 * This sample uses kernel iText functionality that was written in answer to the question.
 * This example will only work starting with iText 5.5.1
 */
package com.itextpdf.samples.sandbox.images;
 
import com.itextpdf.io.image.ImageDataFactory;
import com.itextpdf.kernel.geom.PageSize;
import com.itextpdf.kernel.pdf.CompressionConstants;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Image;
import com.itextpdf.samples.GenericTest;
import com.itextpdf.test.annotations.type.SampleTest;
 
import org.junit.experimental.categories.Category;
 
import java.io.File;
 
@Category(SampleTest.class)
public class FlateCompressJPEG1Pass extends GenericTest {
    public static final String DEST = "./target/test/resources/sandbox/images/flate_compress_jpeg_1pass.pdf";
    public static final String IMAGE = "./src/test/resources/img/berlin2013.jpg";
 
    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new FlateCompressJPEG1Pass().manipulatePdf(DEST);
    }
 
    @Override
    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(new PdfWriter(dest));
 
        // Note that it is not necessary to create new PageSize object,
        // but for testing reasons (connected to parallelization) we call constructor here
        PageSize pageSize = new PageSize(PageSize.A4).rotate();
 
        Document doc = new Document(pdfDoc, pageSize);
 
        Image image = new Image(ImageDataFactory.create(IMAGE));
        image.getXObject().getPdfObject().setCompressionLevel(CompressionConstants.BEST_COMPRESSION);
        image.scaleToFit(PageSize.A4.rotate().getWidth(), pageSize.getHeight());
        image.setFixedPosition(0, 0);
 
        doc.add(image);
 
        doc.close();
    }
}
FlateCompressJPEG2Passes.java
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/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2019 iText Group NV
    Authors: iText Software.
 
    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
/**
 * This sample is written by Bruno Lowagie in answer to the following question:
 * http://stackoverflow.com/questions/21958449/can-itextsharp-generate-pdf-with-jpeg-images-that-are-multi-stage-filtered-both
 * <p>
 * The question was about adding compression to an image that already used /DCTDecode
 */
package com.itextpdf.samples.sandbox.images;
 
import com.itextpdf.kernel.pdf.*;
import com.itextpdf.samples.GenericTest;
import com.itextpdf.test.annotations.type.SampleTest;
 
import org.junit.experimental.categories.Category;
 
import java.io.File;
 
@Category(SampleTest.class)
public class FlateCompressJPEG2Passes extends GenericTest {
    public static final String DEST = "./target/test/resources/sandbox/images/flate_compress_jpeg_2passes.pdf";
    public static final String SRC = "./src/test/resources/pdfs/image.pdf";
 
    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new FlateCompressJPEG2Passes().manipulatePdf(DEST);
    }
 
    @Override
    protected void manipulatePdf(String dest) throws Exception {
        PdfReader reader = new PdfReader(SRC);
        PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(DEST));
 
        PdfDictionary pageDict = pdfDoc.getPage(1).getPdfObject();
        PdfDictionary pageResources = pageDict.getAsDictionary(PdfName.Resources);
        PdfDictionary pageXObjects = pageResources.getAsDictionary(PdfName.XObject);
        PdfName imgName = pageXObjects.keySet().iterator().next();
        PdfStream imgStream = pageXObjects.getAsStream(imgName);
        imgStream.setData(reader.readStreamBytesRaw(imgStream));
 
        PdfArray array = new PdfArray();
        array.add(PdfName.FlateDecode);
        array.add(PdfName.DCTDecode);
        imgStream.put(PdfName.Filter, array);
 
        pdfDoc.close();
    }
}

Click the following link to see the legacy example for iText 5. Except for security fixes, iText 5 is no longer being developed.



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