Convert PDF to thumbnail image in Java [closed]

…衆ロ難τιáo~ 提交于 2019-12-17 10:15:45

问题


Can anybody suggest me a free Java library that can convert a PDF and create a thumbnail image (PNG) from the first page.

Thanks.


回答1:


You could try pdf-renderer it is a pure java solution. The following Code creates an image of the first page.

File pdfFile = new File("/path/to/pdf.pdf");
RandomAccessFile raf = new RandomAccessFile(pdfFile, "r");
FileChannel channel = raf.getChannel();
ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
PDFFile pdf = new PDFFile(buf);
PDFPage page = pdf.getPage(0);

// create the image
Rectangle rect = new Rectangle(0, 0, (int) page.getBBox().getWidth(),
                                 (int) page.getBBox().getHeight());
BufferedImage bufferedImage = new BufferedImage(rect.width, rect.height,
                                  BufferedImage.TYPE_INT_RGB);

Image image = page.getImage(rect.width, rect.height,    // width & height
                            rect,                       // clip rect
                            null,                       // null for the ImageObserver
                            true,                       // fill background with white
                            true                        // block until drawing is done
);
Graphics2D bufImageGraphics = bufferedImage.createGraphics();
bufImageGraphics.drawImage(image, 0, 0, null);
ImageIO.write(bufferedImage, format, new File( "/path/to/image.jpg" ));



回答2:


Excellent sdorra, thanks for your input. I have re-work your example in order to convert all the pages from the pdf.

Hope that will help some of you guys.

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

import javax.imageio.ImageIO;

import com.sun.pdfview.PDFFile;
import com.sun.pdfview.PDFPage;

public class Main {

    public static void main(String[] args) throws IOException {
        File pdfFile = new File("c:\\YOURPDF.pdf");
        RandomAccessFile raf = new RandomAccessFile(pdfFile, "r");
        FileChannel channel = raf.getChannel();
        ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
        PDFFile pdf = new PDFFile(buf);

        for (int i=0; i<pdf.getNumPages(); i++) {
            createImage(pdf.getPage(i), "c:\\PICTURE_" + i + ".jpg");
        }
    }

    public static void createImage(PDFPage page, String destination) throws IOException{
        Rectangle rect = new Rectangle(0, 0, (int) page.getBBox().getWidth(),
                (int) page.getBBox().getHeight());
        BufferedImage bufferedImage = new BufferedImage(rect.width, rect.height,
                         BufferedImage.TYPE_INT_RGB);

        Image image = page.getImage(rect.width, rect.height,    // width & height
                   rect,                       // clip rect
                   null,                       // null for the ImageObserver
                   true,                       // fill background with white
                   true                        // block until drawing is done
        );
        Graphics2D bufImageGraphics = bufferedImage.createGraphics();
        bufImageGraphics.drawImage(image, 0, 0, null);
        ImageIO.write(bufferedImage, "JPG", new File( destination ));
    }

}

You can download the library from pdf-renderer-1.0.5.jar

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来源:https://stackoverflow.com/questions/4929813/convert-pdf-to-thumbnail-image-in-java

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