Question

我想将PDF文档转换为图像。我在使用Ghost4j。

问题： Ghost4J在运行时需要gsdll32.dll文件，我不想要使用dll文件。

问题1：有没有办法，在ghost4j中转换图像而没有dll？

问题2：我在PDFBox API中找到了解决方案。 org.apache.pdfbox.pdmodel.PDPagep have method convertToImage（）`将PDF页面转换为图像格式。

PDDocument doc = PDDocument.load(new File("/document.pdf"));
List<PDPage>pages =  doc.getDocumentCatalog().getAllPages();
PDPage page = pages.get(0);
BufferedImage image =page.convertToImage();
File outputfile = new File("/image.png");
ImageIO.write(image, "png", outputfile);
doc.close();

我在PDF文档上只有文字。当我运行这段代码时，我有这个例外：

Aug 12, 2013 6:00:24 PM org.apache.pdfbox.util.PDFStreamEngine processOperator
INFO: unsupported/disabled operation: BDC
Exception in thread "main" java.lang.ExceptionInInitializerError
    at org.apache.pdfbox.pdmodel.font.PDTrueTypeFont.getawtFont(PDTrueTypeFont.java:481)
    at org.apache.pdfbox.pdmodel.font.PDSimpleFont.drawString(PDSimpleFont.java:109)
    at org.apache.pdfbox.pdfviewer.PageDrawer.processTextPosition(PageDrawer.java:235)
    at org.apache.pdfbox.util.PDFStreamEngine.processEncodedText(PDFStreamEngine.java:496)
    at org.apache.pdfbox.util.operator.ShowTextGlyph.process(ShowTextGlyph.java:62)
    at org.apache.pdfbox.util.PDFStreamEngine.processOperator(PDFStreamEngine.java:554)
    at org.apache.pdfbox.util.PDFStreamEngine.processSubStream(PDFStreamEngine.java:268)
    at org.apache.pdfbox.util.PDFStreamEngine.processSubStream(PDFStreamEngine.java:235)
    at org.apache.pdfbox.util.PDFStreamEngine.processStream(PDFStreamEngine.java:215)
    at org.apache.pdfbox.pdfviewer.PageDrawer.drawPage(PageDrawer.java:125)
    at org.apache.pdfbox.pdmodel.PDPage.convertToImage(PDPage.java:781)
    at org.apache.pdfbox.pdmodel.PDPage.convertToImage(PDPage.java:712)
    at ge.eid.esignature.adessa.pades.sign.PDFtoImage.main(PDFtoImage.java:25)
Caused by: java.lang.IllegalArgumentException
    at java.nio.Buffer.position(Buffer.java:216)
    at sun.font.TrueTypeFont.lookupName(TrueTypeFont.java:1153)
    at sun.font.TrueTypeFont.getPostscriptName(TrueTypeFont.java:1205)
    at java.awt.Font.getPSName(Font.java:1156)
    at org.apache.pdfbox.pdmodel.font.FontManager.loadFonts(FontManager.java:101)
    at org.apache.pdfbox.pdmodel.font.FontManager.<clinit>(FontManager.java:53)
    ... 13 more

Answer 1

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

使用PDF Box将所有pdf页面转换为Java格式的图像格式。

Jar需要pdfbox-1.8.3.jar

或maven依赖

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

以下是解决方案：

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();
    }
}
}

可能将图片转换为jpg, jpeg, png, bmp, gif格式。

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

Answer 2

您可以尝试使用 NonSequentialParser 来避免某些PDF文件出错（使用增量更新）：

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

Answer 3

通过PDFBox的方式是避免本机绑定的好方法。尝试使用PDFBox中的PDFImageWriter，我在几行中做了同样的事情并且它工作得很好。您必须提取PDFDocument并使用它。

PDFImageWriter.write(doc, "png", null, , Integer.MAX_VALUE, "picture");

适用于所有页面。

PDFImageWriter.write(doc, "png", null, 0, 0, "picture");

请参阅： PDFImageWriter Javadoc

Answer 4

您可能尝试转换损坏的PDF文件。当PDF文件包含JPXEncoded流时，我遇到了同样的错误。

Answer 5

您可以使用 PDFBox 轻松将PDF转换为图像。 PDFRenderer PDFBox 类的 renderImageWithDPI 方法用于将pdf转换为图像。

PDDocument doc=PDDocument.load(new File("filepath/sample.pdf"));
PDFRenderer pdfRenderer = new PDFRenderer(doc);
BufferedImage bffim = pdfRenderer.renderImageWithDPI(pageNo, 300, ImageType.RGB);
        String fileName = "image-" + page + ".png";
        ImageIOUtil.writeImage(bim, fileName, 300);

Answer 6

 try {           
                PDDocument document = PDDocument.load(PdfInfo.getPDFWAY());
                if (document.isEncrypted()) {
                    document.decrypt(PdfInfo.getPASSWORD());
                }
                if ("bilevel".equalsIgnoreCase(PdfInfo.getCOLOR())) {
                    PdfInfo.setIMAGETYPE( BufferedImage.TYPE_BYTE_BINARY);
                } else if ("indexed".equalsIgnoreCase(PdfInfo.getCOLOR())) {
                    PdfInfo.setIMAGETYPE(BufferedImage.TYPE_BYTE_INDEXED);
                } else if ("gray".equalsIgnoreCase(PdfInfo.getCOLOR())) {
                    PdfInfo.setIMAGETYPE(BufferedImage.TYPE_BYTE_GRAY);
                } else if ("rgb".equalsIgnoreCase(PdfInfo.getCOLOR())) {
                    PdfInfo.setIMAGETYPE(BufferedImage.TYPE_INT_RGB);
                } else if ("rgba".equalsIgnoreCase(PdfInfo.getCOLOR())) {
                    PdfInfo.setIMAGETYPE(BufferedImage.TYPE_INT_ARGB);
                } else {
                    System.exit(2);
                }
                PDFImageWriter imageWriter = new PDFImageWriter();
                boolean success = imageWriter.writeImage(document, PdfInfo.getIMAGE_FORMAT(),PdfInfo.getPASSWORD(),
                        PdfInfo.getSTART_PAGE(),PdfInfo.getEND_PAGE(),PdfInfo.getOUTPUT_PREFIX(),PdfInfo.getIMAGETYPE(),PdfInfo.getRESOLUTION());
                if (!success) {
                    System.exit(1);
                }
                document.close();

        } catch (IOException | CryptographyException | InvalidPasswordException ex) {
            Logger.getLogger(PdfToImae.class.getName()).log(Level.SEVERE, null, ex);
        }
public class PdfInfo {
    private static String PDFWAY;    
    private static String OUTPUT_PREFIX;
    private static String PASSWORD;
    private static int START_PAGE=1;
    private static int END_PAGE=Integer.MAX_VALUE;
    private static String IMAGE_FORMAT="jpg";
    private static String COLOR="rgb";
    private static int RESOLUTION=256;
    private static int IMAGETYPE=24;
    private static String filename;
    private static String filePath="";
}

Answer 7

对于错误：

org.apache.pdfbox.util.PDFStreamEngine processOperator INFO：不支持/禁用的操作

除了Apache pdfbox jar之外，您需要在类路径中包含fontbox-1.7.1 jar，这将解决您的问题，因为PDFBox内部使用fontbox-1.7.1

将PDF文件转换为图像

7 个答案: