将 PDF 文件转换为图像

您可以轻松地将04-Request-Headers.pdf文件页面转换为图像格式。

使用PDF Box将所有PDF页面转换为Java中的图像格式。

Apache PDFBox 1.8.* 版本解决方案：

Jar required pdfbox-1.8.3.jar

或 maven 依赖性

<dependency>
    <groupId>org.apache.pdfbox</groupId>
    <artifactId>pdfbox</artifactId>
    <version>1.8.3</version>
</dependency>

解决方案如下：

package com.pdf.pdfbox.examples;

import java.awt.image.BufferedImage;
import java.io.File;
import java.util.List;

import javax.imageio.ImageIO;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;

@SuppressWarnings("unchecked")
public class ConvertPDFPagesToImages {
    public static void main(String[] args) {
        try {
        String sourceDir = "C:/Documents/04-Request-Headers.pdf"; // Pdf files are read from this folder
        String destinationDir = "C:/Documents/Converted_PdfFiles_to_Image/"; // converted images from pdf document are saved here

        File sourceFile = new File(sourceDir);
        File destinationFile = new File(destinationDir);
        if (!destinationFile.exists()) {
            destinationFile.mkdir();
            System.out.println("Folder Created -> "+ destinationFile.getAbsolutePath());
        }
        if (sourceFile.exists()) {
            System.out.println("Images copied to Folder: "+ destinationFile.getName());             
            PDDocument document = PDDocument.load(sourceDir);
            List<PDPage> list = document.getDocumentCatalog().getAllPages();
            System.out.println("Total files to be converted -> "+ list.size());

            String fileName = sourceFile.getName().replace(".pdf", "");             
            int pageNumber = 1;
            for (PDPage page : list) {
                BufferedImage image = page.convertToImage();
                File outputfile = new File(destinationDir + fileName +"_"+ pageNumber +".png");
                System.out.println("Image Created -> "+ outputfile.getName());
                ImageIO.write(image, "png", outputfile);
                pageNumber++;
            }
            document.close();
            System.out.println("Converted Images are saved at -> "+ destinationFile.getAbsolutePath());
        } else {
            System.err.println(sourceFile.getName() +" File not exists");
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
}
}

将图像转换为格式的可能。jpg, jpeg, png, bmp, gif

注意：我提到了主要使用的图像格式。

ImageIO.write(image , "jpg", new File( destinationDir +fileName+"_"+pageNumber+".jpg" ));
ImageIO.write(image , "jpeg", new File( destinationDir +fileName+"_"+pageNumber+".jpeg" ));
ImageIO.write(image , "png", new File( destinationDir +fileName+"_"+pageNumber+".png" ));
ImageIO.write(image , "bmp", new File( destinationDir +fileName+"_"+pageNumber+".bmp" ));
ImageIO.write(image , "gif", new File( destinationDir +fileName+"_"+pageNumber+".gif" ));

控制台输出：

Images copied to Folder: Converted_PdfFiles_to_Image
Total files to be converted -> 13
Aug 06, 2014 1:35:49 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_1.png
Aug 06, 2014 1:35:50 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_2.png
Aug 06, 2014 1:35:51 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_3.png
Aug 06, 2014 1:35:51 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_4.png
Aug 06, 2014 1:35:52 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_5.png
Aug 06, 2014 1:35:52 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_6.png
Aug 06, 2014 1:35:53 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_7.png
Aug 06, 2014 1:35:53 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_8.png
Aug 06, 2014 1:35:54 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_9.png
Aug 06, 2014 1:35:54 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_10.png
Aug 06, 2014 1:35:54 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_11.png
Aug 06, 2014 1:35:55 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_12.png
Aug 06, 2014 1:35:55 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: i
Image Created -> 04-Request-Headers_13.png
Converted Images are saved at -> C:\Documents\Converted_PdfFiles_to_Image

Apache PDFBox 2.0.* 版本解决方案：

Required Jars pdfbox-2.0.16.jar， fontbox-2.0.16.jar， commons-logging-1.2.jar

或从 pom.xml 依赖项

<!-- https://mvnrepository.com/artifact/org.apache.pdfbox/pdfbox -->
<dependency>
    <groupId>org.apache.pdfbox</groupId>
    <artifactId>pdfbox</artifactId>
    <version>2.0.16</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.pdfbox/fontbox -->
<dependency>
    <groupId>org.apache.pdfbox</groupId>
    <artifactId>fontbox</artifactId>
    <version>2.0.16</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-logging/commons-logging -->
<dependency>
    <groupId>commons-logging</groupId>
    <artifactId>commons-logging</artifactId>
    <version>1.2</version>
</dependency>

2.0.16 版本的解决方案：

package com.pdf.pdfbox.examples;

import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.ImageType;
import org.apache.pdfbox.rendering.PDFRenderer;

/**
 * 
 * @author venkataudaykiranp
 * 
 * @version 2.0.16(Apache PDFBox version support)
 *
 */
public class ConvertPDFPagesToImages {
    public static void main(String[] args) {
        try {
            String sourceDir = "C:\\Users\\venkataudaykiranp\\Downloads\\04-Request-Headers.pdf"; // Pdf files are read from this folder
            String destinationDir = "C:\\Users\\venkataudaykiranp\\Downloads\\Converted_PdfFiles_to_Image/"; // converted images from pdf document are saved here

            File sourceFile = new File(sourceDir);
            File destinationFile = new File(destinationDir);
            if (!destinationFile.exists()) {
                destinationFile.mkdir();
                System.out.println("Folder Created -> "+ destinationFile.getAbsolutePath());
            }
            if (sourceFile.exists()) {
                System.out.println("Images copied to Folder Location: "+ destinationFile.getAbsolutePath());             
                PDDocument document = PDDocument.load(sourceFile);
                PDFRenderer pdfRenderer = new PDFRenderer(document);

                int numberOfPages = document.getNumberOfPages();
                System.out.println("Total files to be converting -> "+ numberOfPages);

                String fileName = sourceFile.getName().replace(".pdf", "");             
                String fileExtension= "png";
                /*
                 * 600 dpi give good image clarity but size of each image is 2x times of 300 dpi.
                 * Ex:  1. For 300dpi 04-Request-Headers_2.png expected size is 797 KB
                 *      2. For 600dpi 04-Request-Headers_2.png expected size is 2.42 MB
                 */
                int dpi = 300;// use less dpi for to save more space in harddisk. For professional usage you can use more than 300dpi 

                for (int i = 0; i < numberOfPages; ++i) {
                    File outPutFile = new File(destinationDir + fileName +"_"+ (i+1) +"."+ fileExtension);
                    BufferedImage bImage = pdfRenderer.renderImageWithDPI(i, dpi, ImageType.RGB);
                    ImageIO.write(bImage, fileExtension, outPutFile);
                }

                document.close();
                System.out.println("Converted Images are saved at -> "+ destinationFile.getAbsolutePath());
            } else {
                System.err.println(sourceFile.getName() +" File not exists");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

您可以尝试使用非等效解析器来避免某些 PDF 文件（具有增量更新）的错误：

PDDocument doc = PDDocument.loadNonSeq（new File（“/document.pdf”））;