questions.images.ResizeImage.java Source code

Introduction

Here is the source code for questions.images.ResizeImage.java

Source

/*
 * This example was written by Bruno Lowagie, author of the book
 * 'iText in Action' by Manning Publications (ISBN: 1932394796).
 * You can use this example as inspiration for your own applications.
 * The following license applies:
 * http://www.1t3xt.com/about/copyright/index.php?page=MIT
 */

package questions.images;

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.imageio.ImageIO;

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Image;
import com.lowagie.text.PageSize;
import com.lowagie.text.pdf.PRStream;
import com.lowagie.text.pdf.PdfDictionary;
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.PdfStamper;
import com.lowagie.text.pdf.PdfWriter;

public class ResizeImage {

    public static final String RESOURCE = "resources/questions/img/bruno_original.jpg";
    public static final String ORIGINAL = "results/questions/images/original_image_size.pdf";
    public static final String RESULT = "results/questions/images/reduced_image_size.pdf";

    public static void main(String[] args) throws IOException, DocumentException {
        createPdf(ORIGINAL);
        PdfReader reader = new PdfReader(ORIGINAL);
        resizeImagesInPage(reader, 1, 0.5f);
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(RESULT));
        stamper.close();
    }

    public static void createPdf(String filename) throws IOException, DocumentException {
        Document document = new Document(PageSize.A2);
        PdfWriter.getInstance(document, new FileOutputStream(filename));
        document.open();
        Image img = Image.getInstance(RESOURCE);
        document.add(img);
        document.close();
    }

    public static void resizeImagesInPage(PdfReader reader, int page, float factor) throws IOException {
        PdfDictionary pageDictionary = reader.getPageN(page);
        PdfDictionary resources = (PdfDictionary) PdfReader.getPdfObject(pageDictionary.get(PdfName.RESOURCES));
        PdfDictionary xobjects = (PdfDictionary) PdfReader.getPdfObject(resources.get(PdfName.XOBJECT));
        if (xobjects != null) {
            for (Object xObjectKey : xobjects.getKeys()) {
                PdfName xobjectName = (PdfName) xObjectKey;
                PdfObject xobj = xobjects.get(xobjectName);
                PRStream imageStream = (PRStream) PdfReader.getPdfObject(xobj);
                PdfName subtype = (PdfName) PdfReader.getPdfObject(imageStream.get(PdfName.SUBTYPE));
                PdfName filter = (PdfName) PdfReader.getPdfObject(imageStream.get(PdfName.FILTER));
                if (PdfName.IMAGE.equals(subtype) && PdfName.DCTDECODE.equals(filter)) {
                    BufferedImage src = ImageIO
                            .read(new ByteArrayInputStream(PdfReader.getStreamBytesRaw(imageStream)));
                    int width = (int) (src.getWidth() * factor);
                    int height = (int) (src.getHeight() * factor);
                    BufferedImage dest = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
                    AffineTransform at = AffineTransform.getScaleInstance(factor, factor);
                    Graphics2D g = dest.createGraphics();
                    g.drawRenderedImage(src, at);
                    ByteArrayOutputStream newImage = new ByteArrayOutputStream();
                    ImageIO.write(dest, "JPG", newImage);
                    imageStream.setData(newImage.toByteArray(), false, PRStream.NO_COMPRESSION);
                    imageStream.put(PdfName.WIDTH, new PdfNumber(width));
                    imageStream.put(PdfName.HEIGHT, new PdfNumber(height));
                    imageStream.put(PdfName.FILTER, PdfName.DCTDECODE);
                }
            }
        }
    }
}