pdf.Security.DecryptOwnerPassWord(string ownerPassword);
pdf.Security.DecryptUserPassWord();

PdfDocument doc = new PdfDocument();
doc.LoadFromFile(input);
int pageIndex = GetAttachmentPage(doc.Pages, attachmentName);

private int GetAttachmentPage(Spire.Pdf.Widget.PdfPageCollection pageCollection, string fileName)
{
    if (string.IsNullOrEmpty(fileName))
    {
        throw new ArgumentException("fileName is null or empty");
    }
    for (int i = 0; i < pageCollection.Count; i++)
    {
        PdfPageBase page = pageCollection[i];
        for (int j = 0; j < page.AnnotationsWidget.Count; j++)
        {
            Spire.Pdf.Annotations.PdfFileLinkAnnotationWidget pdfFileLinkAnnotationWidget = page.AnnotationsWidget[j] as Spire.Pdf.Annotations.PdfFileLinkAnnotationWidget;
            if (pdfFileLinkAnnotationWidget != null)
            {
                if (fileName.Equals(pdfFileLinkAnnotationWidget.FileName))
                {
                    return i;
                }
            }
        }
    }
    return -1;
}

PdfDocument doc = new PdfDocument(@"input.pdf");
doc.RemoveDocumentJavaScript();
doc.SaveToFile(@"output.pdf", FileFormat.PDF); 

OfdConverter converter = new OfdConverter("inputFile");
converter.ToPdf("outputFile");
converter.ToImage(pageIndex);
converter.ToImage(pageIndex, dpiX, dpiY); 

converter.ToLinearizedPdf("Linearized.pdf");
 PdfDocument pdfDoc = new PdfDocument();
 pdfDoc.LoadFromFile(inputFile);
 Spire.Pdf.PdfPageBase page;
 pdfDoc.FileInfo.IncrementalUpdate = false;
 string MvAddedlaverName1 = "GorLaverPagel";
 for (int iPage = 0; (iPage <= (pdfDoc.Pages.Count - 1)); iPage++)
 {
     page = pdfDoc.Pages[iPage];
     Spire.Pdf.Graphics.Layer.PdfLayer wtLaver_1 = pdfDoc.Layers.AddLayer(MvAddedlaverName1);
     wtLaver_1.ViewState = LayerViewState.Allways;
     wtLaver_1.PrintState = LayerPrintState.Nerver;
     wtLaver_1.ExportState = LayerExportState.ExportWhenVisible;
     Spire.Pdf.Graphics.PdfCanvas gPdfCanvas_1 = wtLaver_1.CreateGraphics(page.Canvas);
     gPdfCanvas_1.SetTransparency(0.4f);
     gPdfCanvas_1.DrawString(tStatusString, new PdfFont(PdfFontFamily.Helvetica, 28), new PdfSolidBrush(Color.Black), new System.Drawing.PointF(((page.Size.Width - 265) - (524 / 2)), (page.Size.Height - (50 - 127))));
     wtLaver_1.CreateGraphics(gPdfCanvas_1);
     gPdfCanvas_1.SetTransparency(1);
 }
 pdfDoc.SaveToFile(outputFile, FileFormat.PDF);
 pdfDoc.Close();

System.Collections.Generic.List<int[]> inkList = new System.Collections.Generic.List<int[]>();
 int[] intPoints = new int[]
 {
       100,800,
       200,800,
       200,700
 };
 inkList.Add(intPoints);
 PdfInkAnnotation ia = new PdfInkAnnotation(inkList);
 ia.Color = Color.LightBlue;
 ia.Border.Width = 12;
 ia.Opacity = 0.3f;
 ia.Text = "e-iceblue";
 pdfPage.AnnotationsWidget.Add(ia);

ISlide sld = ppt.Slides[0] as ISlide;
FillFormat bg = sld.DisplaySlideBackground.GetBackgroundFillFormat(sld as ActiveSlide);
switch (bg.FillType)
{
    case FillFormatType.Solid:
        sb.AppendLine("type：" + bg.FillType + "\tcolor：" + bg.SolidColor.Color);
        break;
    case FillFormatType.Gradient:
        sb.AppendLine("type：" + bg.FillType);
        foreach (GradientStop stop in bg.Gradient.GradientStops)
        {
            sb.AppendLine("position：" + stop.Position + "\tcolor：" + stop.Color.Color);
        }
        break;
    default:
        sb.AppendLine("type：" + bg.FillType);
        break;
}

Presentation.HighQualityImage = true;