利用jpedal进行pdf转换成jpeg,jpg,png,tiff,tif等格式的图片

 项目中运用到pdf文件转换成image图片,开始时使用pdfbox开源库进行图片转换,但是转换出来的文件中含有部分乱码的情况.下面是pdfBox 的pdf转换图片的代码示例.

try{               String password = null;                    int startPage = 1;           String imageType = "jpg";             File imageFile = new File("E:\\upload\\pdf\\20140424\\Servlet."+ imageType);                              File pdfFile = new File("E:\\upload\\pdf\\20140424\\Servlet.pdf");            PDDocument document = PDDocument.load(pdfFile);       endPage = document.getPageCount();       PDFImageWriter imageWriter = new PDFImageWriter();       imageWriter.writeImage(document,imageType,password,startPage, endPage,imageFile.getAbsolutePath());       document.close();              }catch(IOException  e){      e.printStackTrace();              }     

比较了其他的开源库之后,准备采用jpedal。但是jpedal的治疗非常少，除了官方网站外，即使是英文资料也很少。而且官方提供的代码示例中的一些方法在的lgpl授权的
jpeal的代码库中不存在。下面是收集到的一些资料

1、jpedal文档：http://javadoc.idrsolutions.com/org/jpedal/PdfDecoder.html

2、简单调用示例：http://www.idrsolutions.com/java-pdf-code-faq/#pdf2img
3、lgpl授权的jpedal库的下载地址：http://sourceforge.net/projects/jpedal/
4、转换示例示例地址：http://files.idrsolutions.com/samplecode/org/jpedal/examples/images/ConvertPagesToImages.java.html

5、高清图片转换示例地址：http://files.idrsolutions.com/samplecode/org/jpedal/examples/images/ConvertPagesToHiResImages.java.html

        于是稍微修改了官方的转换示例，下面是经过测试可以使用的转换代码

import cn.com.pujiConvert.util.Common;    import com.sun.imageio.plugins.jpeg.JPEGImageWriter;  import org.jpedal.*;  import org.jpedal.color.ColorSpaces;  import org.jpedal.constants.PageInfo;  import org.jpedal.exception.PdfException;  import org.jpedal.external.Options;  import org.jpedal.fonts.FontMappings;  import org.jpedal.objects.PdfFileInformation;  import org.jpedal.utils.LogWriter;  import org.w3c.dom.Element;    import javax.imageio.IIOImage;  import javax.imageio.ImageIO;  import javax.imageio.ImageTypeSpecifier;  import javax.imageio.metadata.IIOMetadata;  import javax.imageio.plugins.jpeg.JPEGImageWriteParam;  import javax.imageio.stream.ImageOutputStream;  import java.awt.*;  import java.awt.image.BufferedImage;  import java.io.*;  import java.util.Iterator;    public class ConvertPagesToImages{            /**      * show if image transparent       */      boolean isTransparent=false;            /**output where we put files */      private String user_dir = System.getProperty("user.dir");            /**use 96 dpi as default so pages correct size (72 will be smaller) */      private float pageScaling =1.33f;            /**flag to show if we print messages */      public static boolean outputMessages = false;            String output_dir=null;            /**correct separator for OS */      String separator = System.getProperty("file.separator");            /**the decoder object which decodes the pdf and returns a data object */      PdfDecoder decode_pdf = null;            //type of image to save thumbnails      private String format = "png";            /** holding all creators that produce OCR pdf's ocr*/      private String[] ocr = {"TeleForm"};            /**scaling to use - default is 100 percent */      private int scaling=100;            /**file password or null */      private String password=null;            //only used if between 0 and 1       private float JPEGcompression=-1f;            private int pageCount = 0;            public ConvertPagesToImages() {         }            public void init(String file_name, int scaling, String format, String output_dir, String password, int pageCount){          /*缩小比率*/          this.scaling = scaling;          /*图片格式*/          this.format = format;          /*输出目录*/          this.output_dir = output_dir;          /*pdf密码*/          this.password = password;          /*输出图片数*/          this.pageCount = pageCount;                    /*判断文件是否存在*/          File pdf_file = new File(file_name);          if (!pdf_file.exists()) {              System.out.println("File " + pdf_file + " not found");              System.out.println("May need full path");                            return;          }                   extraction(file_name, output_dir);         }            private void extraction(String file_name, String output_dir) {                  this.output_dir=output_dir;            if (!user_dir.endsWith(separator)){              user_dir = user_dir + separator;          }                    if (file_name.toLowerCase().endsWith(".pdf")) {                            if(output_dir==null){                  output_dir=user_dir + "thumbnails" + separator;              }                            decodeFile(file_name,output_dir);          } else {              String[] files = null;              File inputFiles;                            if (!file_name.endsWith(separator)){                  file_name = file_name + separator;              }                            try {                  inputFiles = new File(file_name);                                    if (!inputFiles.isDirectory()) {                      System.err.println(file_name + " is not a directory. Exiting program");                  }else{                      files = inputFiles.list();                  }              } catch (Exception ee) {                  LogWriter.writeLog("Exception trying to access file " + ee.getMessage());                                }                            if(files!=null){                  for (String file : files) {                                            if (file.toLowerCase().endsWith(".pdf")) {                          if (outputMessages){                              System.out.println(file_name + file);                          }                                                    decodeFile(file_name + file, output_dir);                      }                  }              }          }                    if(outputMessages){              System.out.println("Thumbnails created");          }      }            /**      * routine to decode a file       */      private void decodeFile(String file_name,String output_dir) {          String name = "demo"; //set a default just in case                    int pointer = file_name.lastIndexOf(separator);                    if(pointer==-1){              pointer = file_name.lastIndexOf('/');          }                    if (pointer != -1){              name = file_name.substring(pointer + 1, file_name.length() - 4);          }else if((file_name.toLowerCase().endsWith(".pdf"))){              name=file_name.substring(0,file_name.length()-4);          }                    //fix for odd files on Linux created when you view pages          if(name.startsWith(".")){              return;          }                    //create output dir for images          if(output_dir==null){              output_dir = user_dir + "thumbnails" + separator ;          }                    //PdfDecoder returns a PdfException if there is a problem          try {              if(decode_pdf==null){                  decode_pdf = new PdfDecoder(true);              }                            /**optional JAI code for faster rendering*/              org.jpedal.external.ImageHandler myExampleImageHandler=new org.jpedal.examples.handlers.ExampleImageDrawOnScreenHandler();              decode_pdf.addExternalHandler(myExampleImageHandler, Options.ImageHandler);                            //mappings for non-embedded fonts to use              FontMappings.setFontReplacements();                //true as we are rendering page              decode_pdf.setExtractionMode(0, pageScaling);              //don't bother to extract text and images                            /**              * open the file (and read metadata including pages in  file)              */              if (outputMessages){                  System.out.println("Opening file :" + file_name);              }                            if(password != null && password != ""){                  decode_pdf.openPdfFile(file_name,password);              }else{                  decode_pdf.openPdfFile(file_name);              }                        } catch (Exception e) {              System.err.println("8.Exception " + e + " in pdf code in "+file_name);          }                    /**          * extract data from pdf (if allowed).          */          if(decode_pdf.isEncrypted() && !decode_pdf.isFileViewable()){              throw new RuntimeException("Wrong password password used=>"+password+ '<');          }else if ((decode_pdf.isEncrypted()&&(!decode_pdf.isPasswordSupplied())) && (!decode_pdf.isExtractionAllowed())) {              throw new RuntimeException("Extraction not allowed");          } else {              extractPageAsImage(file_name, output_dir, name, isTransparent);          }                    /**close the pdf file */          decode_pdf.closePdfFile();         }            private void extractPageAsImage(String file_name, String output_dir, String name, boolean isTransparent) {             //create a directory if it doesn't exist          File output_path = new File(output_dir);          if (!output_path.exists()){              output_path.mkdirs();          }                    boolean isSingleOutputFile=false;          boolean compressTiffs = false;          String rawJPEGComp = null;             String jpgFlag = "96";                            //page range          int start = 1,  end = decode_pdf.getPageCount();                    end = (pageCount == 0) ? end : pageCount;                    if (outputMessages){              System.out.println("Thumbnails will be in  " + output_dir);          }                    try {              BufferedImage[] multiPages = new BufferedImage[1 + (end - start)];                            for (int page = start; page < end + 1; page++){                  getPage(output_dir, name, isTransparent, isSingleOutputFile,rawJPEGComp, jpgFlag, compressTiffs, start, end,multiPages, page);              }          } catch (Exception e) {              decode_pdf.closePdfFile();              throw new RuntimeException("Exception " + e.getMessage()+" with thumbnails on File="+file_name);          }      }            private void getPage(              String output_dir,               String name,               boolean isTransparent,              boolean isSingleOutputFile,               String rawJPEGComp,               String jpgFlag,              boolean compressTiffs,               int start,               int end,              BufferedImage[] multiPages,               int page      ) throws PdfException, IOException, FileNotFoundException {          if (outputMessages ){              System.out.println("Page " + page);          }                    /**          * 补0操作          */          String pageAsString = String.valueOf(page);          String maxPageSize  = String.valueOf(end);          int padding         = maxPageSize.length()-pageAsString.length();                        for(int ii = 0; ii < padding; ii++){              pageAsString = '0' + pageAsString;          }                    String image_name;          if(isSingleOutputFile){              image_name =name;          }else{              image_name =name+"_page_" + pageAsString;          }                    /**          * get PRODUCER and if OCR disable text printing          */          PdfFileInformation currentFileInformation = decode_pdf.getFileInformationData();                    String[] values=currentFileInformation.getFieldValues();          String[] fields=PdfFileInformation.getFieldNames();                        for(int i=0;i<fields.length;i++){              if(fields[i].equals("Creator")){                        for (String anOcr : ocr) {                        if (values[i].equals(anOcr)) {                                                     decode_pdf.setRenderMode(PdfDecoder.RENDERIMAGES);                                                  }                  }              }          }                        BufferedImage image_to_save;          if(!isTransparent){              image_to_save=decode_pdf.getPageAsImage(page);          }else{               //use this if you want a transparent image               image_to_save =decode_pdf.getPageAsTransparentImage(page);                            //java adds odd tint if you save this as JPEG which does not have transparency              // so put as RGB on white background              // (or save as PNG or TIFF which has transparency)              // or just call decode_pdf.getPageAsImage(page)              if(image_to_save!=null && format.toLowerCase().startsWith("jp")){                                    BufferedImage rawVersion=image_to_save;                                    int w=rawVersion.getWidth(), h=rawVersion.getHeight();                  //blank canvas                  image_to_save = new BufferedImage(w,h , BufferedImage.TYPE_INT_RGB);                                    //                  Graphics2D g2 = image_to_save.createGraphics();                  //white background                  g2.setPaint(Color.WHITE);                  g2.fillRect(0,0,w,h);                  //paint on image                  g2.drawImage(rawVersion, 0, 0,null);              }          }                    /*if just gray we can reduce memory usage by converting image to Grayscale                   @SuppressWarnings("rawtypes")         Iterator colorspacesUsed = decode_pdf.getPageInfo(PageInfo.COLORSPACES);                  int nextID;         boolean isGrayOnly=colorspacesUsed!=null; //assume true and disprove         while(colorspacesUsed!=null && colorspacesUsed.hasNext()){             nextID= (Integer) (colorspacesUsed.next());                          if(nextID!= ColorSpaces.DeviceGray && nextID!=ColorSpaces.CalGray){                 isGrayOnly=false;             }         }                  //draw onto GRAY image to reduce colour depth         if(isGrayOnly){             BufferedImage image_to_save2=new BufferedImage(image_to_save.getWidth(),image_to_save.getHeight(), BufferedImage.TYPE_BYTE_GRAY);             image_to_save2.getGraphics().drawImage(image_to_save,0,0,null);             image_to_save = image_to_save2;         }                  //put image in array if multi-images         if(isSingleOutputFile){             multiPages[page-start] = image_to_save;         }                  if (image_to_save != null) {                          /**BufferedImage does not support any dpi concept. A higher dpi can be created              * using JAI to convert to a higher dpi image*/                            //shrink the page to 50% with graphics2D transformation              //- add your own parameters as needed              //you may want to replace null with a hints object if you              //want to fine tune quality.                            /** example 1 biliniear scaling              AffineTransform scale = new AffineTransform();              scale.scale(.5, .5); //50% as a decimal              AffineTransformOp scalingOp =new AffineTransformOp(scale, null);              image_to_save =scalingOp.filter(image_to_save, null);               */                            /** example 2 bicubic scaling - better quality but slower              to preserve aspect ratio set newWidth or newHeight to -1*/                            /**allow user to specify maximum dimension for thumbnail*/              int maxDimension = -1;                            if(scaling!=100 || maxDimension != -1){                  int newWidth=image_to_save.getWidth()*scaling/100;                  int newHeight=image_to_save.getHeight()*scaling/100;                                    Image scaledImage;                  if(maxDimension != -1 && (newWidth > maxDimension || newHeight > maxDimension)){                      if(newWidth > newHeight){                          newWidth = maxDimension;                          scaledImage= image_to_save.getScaledInstance(newWidth,-1,BufferedImage.SCALE_SMOOTH);                      } else {                          newHeight = maxDimension;                          scaledImage= image_to_save.getScaledInstance(-1,newHeight,BufferedImage.SCALE_SMOOTH);                      }                  } else {                      scaledImage= image_to_save.getScaledInstance(newWidth,-1,BufferedImage.SCALE_SMOOTH);                  }                                    if(format.toLowerCase().startsWith("jp")){                      image_to_save = new BufferedImage(scaledImage.getWidth(null),scaledImage.getHeight(null) , BufferedImage.TYPE_INT_RGB);                  }else{                      image_to_save = new BufferedImage(scaledImage.getWidth(null),scaledImage.getHeight(null) , BufferedImage.TYPE_INT_ARGB);                  }                                    Graphics2D g2 = image_to_save.createGraphics();                                    g2.drawImage(scaledImage, 0, 0,null);              }                if (format.startsWith("jp")) {                  saveAsJPEG(jpgFlag, image_to_save, JPEGcompression, new BufferedOutputStream(new FileOutputStream(output_dir + pageAsString + image_name + '.' + format)));                              } else {                  //save image                  decode_pdf.getObjectStore().saveStoredImage(                          output_dir + pageAsString + image_name,                          image_to_save,                          true,                          false,                          format);              }             }                    //flush images in case we do more than 1 page so only contains          //images from current page          decode_pdf.flushObjectValues(true);                  }            private static void saveAsJPEG(String jpgFlag,BufferedImage image_to_save, float JPEGcompression, BufferedOutputStream fos) throws IOException {          JPEGImageWriter imageWriter = (JPEGImageWriter) ImageIO.getImageWritersBySuffix("jpeg").next();          ImageOutputStream ios = ImageIO.createImageOutputStream(fos);          imageWriter.setOutput(ios);                    IIOMetadata imageMetaData = imageWriter.getDefaultImageMetadata(new ImageTypeSpecifier(image_to_save), null);                    if (Common.isInteger(jpgFlag)){                            int dpi = 96;                            try {                  dpi = Integer.parseInt(jpgFlag);              } catch (Exception e) {                  e.printStackTrace();              }                            Element tree = (Element) imageMetaData.getAsTree("javax_imageio_jpeg_image_1.0");              Element jfif = (Element)tree.getElementsByTagName("app0JFIF").item(0);              jfif.setAttribute("Xdensity", Integer.toString(dpi));              jfif.setAttribute("Ydensity", Integer.toString(dpi));          }                    JPEGImageWriteParam jpegParams = (JPEGImageWriteParam) imageWriter.getDefaultWriteParam();          if(JPEGcompression>=0 && JPEGcompression<=1f){                   jpegParams.setCompressionMode(JPEGImageWriteParam.MODE_EXPLICIT);              jpegParams.setCompressionQuality(JPEGcompression);                        }                    imageWriter.write(imageMetaData, new IIOImage(image_to_save, null, null), jpegParams);          ios.close();          imageWriter.dispose();      }             public static void main(String[] args) {              long start=System.currentTimeMillis();                          String pdfPath = "E:\\upload\\pdf\\20140424\\Servlet.pdf";           int scaling = -1;           String format = "jpg";           String output_dir = "E:\\upload\\pdf\\20140424\\jpg\\";           String password = null;           int pageCount = 10;             ConvertPagesToImages convertPagesToImages = new ConvertPagesToImages();           convertPagesToImages.init(pdfPath, scaling, format, output_dir, password, pageCount);                  System.out.println("花费时间为="+(System.currentTimeMillis()-start)/1000 + "秒");      }           }  

功能说明：

       1、支持对文件夹下的所有pdf转换成图片，同时也支持对单个pdf进行转换操作。

       2、支持转换成jpg，jpeg，tiff，tif，png格式的图片

       3、支持指定转换的图片数。

       4、支持指定图片的存储位置

传入参数说明

 1、pdfPath pdf文件绝对路径，可以是pdf所在的目录也可以是pdf文件路径  
 2、format  图片格式 (支持jpg,jpeg,tiff,png) ，传参时不能带有点号
 3、scaling 图片比率从1到100(100 = 全尺寸) 支持设置为-1 将保持高质量
 4、output_dir 输出路径，输出路径为绝对路径
 5、password 文件密码 若没有传入null值