在C＃中将PDF导出为JPG [关闭]

5 回答

• 5

  看看Ghostscript . 您可以使用它将PDF渲染到图像 .

  http://www.mattephraim.com/blog/2009/01/06/a-simple-c-wrapper-for-ghostscript/

  回复于 2024-04-29T19:10:26+08:00
• 2

  Ghostscript目前是渲染PDF的事实上的标准 . 即使使用GhostScriptSharp，包装也有点棘手 .

  Jason Morse写了一个great C# wrapper for rendering PDFs作为开源imageresizing.net library的插件 .

  如果它是一个asp.net应用程序，库允许动态渲染，所以你只需添加一个查询字符串来获取jpeg / png版本：

  /pdfs/letter.pdf?format=jpg&page=2

  您也可以使用托管API（在任何应用程序类型中 - 不是特定于asp.net）

  ImageBuilder.Current.Build（“letter.pdf”，“dest.jpg”，new ResizeSettings（“format = jpg; page = 2”））;

  PdfRenderer插件是GPL许可的，就像Ghostscript一样 .

  回复于 2024-04-29T19:10:26+08:00
• 1

  ABCpdf使用C＃将PDF文档导出为JPEG . 见：http://www.websupergoo.com/helppdfnet/source/4-examples/19-rendering.htm

  回复于 2024-04-29T19:10:26+08:00
• 0

  （免责声明：我为Atalasoft工作并写了很多PDF技术）如果你在Atalasoft dotImage中使用PdfDecoder，这很简单：

  public void PdfToJpegThumb(Stream srcStream, int pageNo, int maxDimension, Stream dstStream)
  {
      PdfDecoder decoder = new PdfDecoder();
      decoder.Resolution = 96; // reduce default resolution to speed up rendering
      // render page
      using (AtalaImage pdfimage = decoder.read(srcStream, pageNo, null)) {
          Thumbnail tn = new Thumbnail(maxDimension, maxDimension);
          // make a thumbnail image
          using (AtalaImage tnImage = tn.Create(pdfImage)) {
              // save it
              tnImage.Save(dstStream, new JpegEncoder(), null);
          }
      }
  }
  

  回复于 2024-04-29T19:10:26+08:00
• 5

  我从网上的某个地方得到了这个 - 不记得确切的位置，但它对我有用！
  我把它变成了一个很好的功能 .

  它使用GhostScript API（GSdll32.dll）

  imageFormat参数的示例是"jpeg"，"tiff32nc"等 .

  #region GhostScript API functions
      [DllImport("gsdll32.dll", EntryPoint = "gsapi_new_instance")]
      private static extern int CreateAPIInstance(out IntPtr pinstance,
                                              IntPtr caller_handle);
  
      [DllImport("gsdll32.dll", EntryPoint = "gsapi_init_with_args")]
      private static extern int InitAPI(IntPtr instance, int argc, IntPtr argv);
  
      [DllImport("gsdll32.dll", EntryPoint = "gsapi_exit")]
      private static extern int ExitAPI(IntPtr instance);
  
      [DllImport("gsdll32.dll", EntryPoint = "gsapi_delete_instance")]
      private static extern void DeleteAPIInstance(IntPtr instance);
      #endregion
  
      public bool CreateImage(string inputPath, string outputPath, string imageFormat, int firstPage, int lastPage, int width, int height)
      {
          bool result = false;
          try
          {
              string[] args = GetArgs(inputPath, outputPath, imageFormat, firstPage, lastPage, width, height);
              var argStrHandles = new GCHandle[args.Length];
              var argPtrs = new IntPtr[args.Length];
  
              // Create a handle for each of the arguments after 
              // they've been converted to an ANSI null terminated
              // string. Then store the pointers for each of the handles
              for (int i = 0; i < args.Length; i++)
              {
                  argStrHandles[i] = GCHandle.Alloc(StringToAnsi(args[i]), GCHandleType.Pinned);
                  argPtrs[i] = argStrHandles[i].AddrOfPinnedObject();
              }
  
              // Get a new handle for the array of argument pointers
              var argPtrsHandle = GCHandle.Alloc(argPtrs, GCHandleType.Pinned);
  
              // Get a pointer to an instance of the GhostScript API 
              // and run the API with the current arguments
              IntPtr gsInstancePtr;
              CreateAPIInstance(out gsInstancePtr, IntPtr.Zero);
              InitAPI(gsInstancePtr, args.Length, argPtrsHandle.AddrOfPinnedObject());
  
              // Cleanup arguments in memory
              for (int i = 0; i < argStrHandles.Length; i++)
                  argStrHandles[i].Free();
  
              argPtrsHandle.Free();
  
              // Clear API
              ExitAPI(gsInstancePtr);
              DeleteAPIInstance(gsInstancePtr);
  
              result = true;
          }
          catch(Exception e)
          {
              throw e;
          }
          return result;
      }
  

  回复于 2024-04-29T19:10:26+08:00