private ImageCodecInfo GetEncoder(ImageFormat format)
		{

			ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();

			foreach (ImageCodecInfo codec in codecs)
			{
				if (codec.FormatID == format.Guid)
				{
					return codec;
				}
			}
			return null;
		}

		private void CompressPdf(string InFile, string OutFile)
		{
			PdfReader reader = new PdfReader(InFile);
			using (FileStream fs = new FileStream(OutFile, FileMode.Create))
			{

				int n = reader.XrefSize;
				PdfObject obj;
				PRStream stream;
				for (int i = 0; i < n; i++)
				{
					obj = reader.GetPdfObject(i);
					if (obj == null || !obj.IsStream()) continue;
					stream = (PRStream)obj;

					PdfObject pdfsubtype = stream.Get(PdfName.SUBTYPE);
					if (pdfsubtype != null && pdfsubtype.ToString().Equals(PdfName.IMAGE.ToString()))
					{


						byte[] steambytes = PdfReader.GetStreamBytesRaw(stream);
						Stream st = new MemoryStream(steambytes);

						Bitmap image = new Bitmap(st);
						ImageCodecInfo jpgEncoder = GetEncoder(ImageFormat.Jpeg);

						System.Drawing.Imaging.Encoder myEncoder =
							 System.Drawing.Imaging.Encoder.Quality;

						EncoderParameters myEncoderParameters = new EncoderParameters(1);

						EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 20L); //уровень сжатия
						myEncoderParameters.Param[0] = myEncoderParameter;
						byte[] buff;
						using (MemoryStream outst = new MemoryStream())
						{
							image.Save(outst, jpgEncoder, myEncoderParameters);
							outst.Position = 0;
							buff = outst.ToArray();
						}
						stream.SetData(buff, false, PRStream.BEST_COMPRESSION);
						stream.Put(PdfName.TYPE, PdfName.XOBJECT);
						stream.Put(PdfName.SUBTYPE, PdfName.IMAGE);
						stream.Put(PdfName.FILTER, PdfName.DCTDECODE);
						stream.Put(PdfName.WIDTH, new PdfNumber(image.Width));
						stream.Put(PdfName.HEIGHT, new PdfNumber(image.Height));
						stream.Put(PdfName.BITSPERCOMPONENT, new PdfNumber(8));
						stream.Put(PdfName.COLORSPACE, PdfName.DEVICERGB);
					}

				}
				reader.RemoveUnusedObjects();
				PdfStamper stamper = new PdfStamper(reader, fs);
				stamper.SetFullCompression();
				stamper.Close();
			}
			reader.Close();
		}