PDFBox：将pdf页面转换为图像的问题

我的任务非常简单：将pdf文件的每一页转换为图像。 我尝试使用icepdf开源版本来生成图像，但它们不会生成具有正确字体的图像。 所以我开始使用PDFBox。 代码如下：

PDDocument document = PDDocument.load(new File("testing.pdf")); List pages = document.getDocumentCatalog().getAllPages(); for (int i = 0; i < pages.size(); i++) { PDPage singlePage = pages.get(i); BufferedImage buffImage = convertToImage(singlePage, 8, 12); ImageIO.write(buffImage, "png", new File(PdfUtil.DATA_OUTPUT_DIR+(count++)+".png")); } 

字体看起来不错，但pdf文件中的图片看起来很晕眩（参见附件）。 我查看源代码，但我仍然不知道如何解决它。 你们有什么想法发生了什么事吗？ 请帮忙。 谢谢！！

Answer 1

使用pdfbox将PDF文件04-Request-Headers.pdf转换为图像。

下载此文件并将其粘贴到Documents文件夹中。

例：

 package com.pdf.pdfbox.test; import java.awt.HeadlessException; import java.awt.Toolkit; import java.awt.image.BufferedImage; import java.io.File; import java.util.List; import org.apache.pdfbox.pdmodel.PDDocument; import org.apache.pdfbox.pdmodel.PDPage; import org.apache.pdfbox.util.PDFImageWriter; public class ConvertPDFPageToImageWithoutText { public static void main(String[] args) { try { String oldPath = "C:/Documents/04-Request-Headers.pdf"; File oldFile = new File(oldPath); if (oldFile.exists()) { PDDocument document = PDDocument.load(oldPath); @SuppressWarnings("unchecked") List list = document.getDocumentCatalog().getAllPages(); String fileName = oldFile.getName().replace(".pdf", ""); String imageFormat = "png"; String password = ""; int startPage = 1; int endPage = list.size(); String outputPrefix = "C:/Documents/PDFCopy/";//converted images saved here File file = new File(outputPrefix); if (!file.exists()) { file.mkdirs(); } int imageType = 24; String color = "rgb"; int resolution; try { resolution = Toolkit.getDefaultToolkit().getScreenResolution(); } catch (HeadlessException e) { resolution = 96; } if ("bilevel".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_BYTE_BINARY; } else if ("indexed".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_BYTE_INDEXED; } else if ("gray".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_BYTE_GRAY; } else if ("rgb".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_INT_RGB; } else if ("rgba".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_INT_ARGB; } else { System.err.println("Error: the number of bits per pixel must be 1, 8 or 24."); } PDFImageWriter pdfImageWriter = new PDFImageWriter(); boolean imageWriter = pdfImageWriter.writeImage(document, imageFormat, password, startPage, endPage, outputPrefix + fileName, imageType, resolution); if (!imageWriter) { throw new Exception("No writer found for format '" + imageFormat + "'"); } document.close(); } else { System.err.println(oldPath +" File Can't be found"); } } catch (Exception e) { e.printStackTrace(); } } 

}

要么

尝试使用以下解决方案将pdf文件转换为图像格式。

如何在java中使用PDF渲染器将PDF转换为具有分辨率的图像

Answer 2

使用以下代码进行转换它工作正常！

  import java.awt.HeadlessException; import java.awt.Toolkit; import java.awt.image.BufferedImage; import javax.imageio.ImageIO; import org.apache.pdfbox.exceptions.InvalidPasswordException; import org.apache.pdfbox.pdmodel.PDDocument; import org.apache.pdfbox.util.PDFImageWriter; /** * Convert a PDF document to an image. * * @author Ben Litchfield * @version $Revision: 1.6 $ */ public class PDFToImage { private static final String PASSWORD = "-password"; private static final String START_PAGE = "-startPage"; private static final String END_PAGE = "-endPage"; private static final String IMAGE_FORMAT = "-imageType"; private static final String OUTPUT_PREFIX = "-outputPrefix"; private static final String COLOR = "-color"; private static final String RESOLUTION = "-resolution"; /** * private constructor. */ private PDFToImage() { //static class } /** * Infamous main method. * * @param args Command line arguments, should be one and a reference to a file. * * @throws Exception If there is an error parsing the document. */ public static void main( String[] args ) throws Exception { String password = ""; String pdfFile = "D:/docoverview.pdf"; String outputPrefix = "D:/printdata/pdfimages/"; String imageFormat = "jpg"; int startPage = 1; int endPage = Integer.MAX_VALUE; String color = "rgb"; int resolution; try { resolution = Toolkit.getDefaultToolkit().getScreenResolution(); } catch( HeadlessException e ) { resolution = 96; } for( int i = 0; i < args.length; i++ ) { if( args[i].equals( PASSWORD ) ) { i++; if( i >= args.length ) { usage(); } password = args[i]; } else if( args[i].equals( START_PAGE ) ) { i++; if( i >= args.length ) { usage(); } startPage = Integer.parseInt( args[i] ); } else if( args[i].equals( END_PAGE ) ) { i++; if( i >= args.length ) { usage(); } endPage = Integer.parseInt( args[i] ); } else if( args[i].equals( IMAGE_FORMAT ) ) { i++; imageFormat = args[i]; } else if( args[i].equals( OUTPUT_PREFIX ) ) { i++; outputPrefix = args[i]; } else if( args[i].equals( COLOR ) ) { i++; color = args[i]; } else if( args[i].equals( RESOLUTION ) ) { i++; resolution = Integer.parseInt(args[i]); } else { if( pdfFile == null ) { pdfFile = args[i]; } } } if( pdfFile == null ) { usage(); } else { if(outputPrefix == null) { outputPrefix = pdfFile.substring( 0, pdfFile.lastIndexOf( '.' )); } PDDocument document = null; try { document = PDDocument.load( pdfFile ); //document.print(); if( document.isEncrypted() ) { try { document.decrypt( password ); } catch( InvalidPasswordException e ) { if( args.length == 4 )//they supplied the wrong password { System.err.println( "Error: The supplied password is incorrect." ); System.exit( 2 ); } else { //they didn't supply a password and the default of "" was wrong. System.err.println( "Error: The document is encrypted." ); usage(); } } } int imageType = 24; if ("bilevel".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_BYTE_BINARY; } else if ("indexed".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_BYTE_INDEXED; } else if ("gray".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_BYTE_GRAY; } else if ("rgb".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_INT_RGB; } else if ("rgba".equalsIgnoreCase(color)) { imageType = BufferedImage.TYPE_INT_ARGB; } else { System.err.println( "Error: the number of bits per pixel must be 1, 8 or 24." ); System.exit( 2 ); } //Make the call PDFImageWriter imageWriter = new PDFImageWriter(); boolean success = imageWriter.writeImage(document, imageFormat, password, startPage, endPage, outputPrefix, imageType, resolution); if (!success) { System.err.println( "Error: no writer found for image format '" + imageFormat + "'" ); System.exit(1); } } catch (Exception e) { System.err.println(e); } finally { if( document != null ) { document.close(); } } } } /** * This will print the usage requirements and exit. */ private static void usage() { System.err.println( "Usage: java org.apache.pdfbox.PDFToImage [OPTIONS] \n" + " -password  Password to decrypt document\n" + " -imageType  (" + getImageFormats() + ")\n" + " -outputPrefix 
 Filename prefix for image files\n" + " -startPage  The first page to start extraction(1 based)\n" + " -endPage  The last page to extract(inclusive)\n" + " -color  The color depth (valid: bilevel, indexed, gray, rgb, rgba)\n" + " -resolution  The bitmap resolution in dpi\n" + "  The PDF document to use\n" ); System.exit(1); } private static String getImageFormats() { StringBuffer retval = new StringBuffer(); String[] formats = ImageIO.getReaderFormatNames(); for( int i = 0; i < formats.length; i++ ) { retval.append( formats[i] ); if( i + 1 < formats.length ) { retval.append( "," ); } } return retval.toString(); } } 

Answer 3

我最终尝试了不同的pdf库。 最好的解决方案是使用“JPedal”，但您只能免费获得试用版。 您也可以免费试用icepdf，但它可能无法生成正确的字体。