PdfDocument doc = new PdfDocument();
doc.LoadFromFile("input.pdf");
doc.ConvertOptions.SetPdfToImageOptions(0);
Image image = doc.SaveAsImage(0);
image.Save("output.png", ImageFormat.Png);

static void Main(string[] args)
{
    X509Certificate2 x509 = new X509Certificate2(inputFile_pfx, password);
    PdfDocument doc = new PdfDocument();
    doc.LoadFromFile(inputFile);
    PdfPKCS7Formatter formatter = new PdfPKCS7Formatter(x509, false);
    formatter.TimestampService = new TSAHttpService("http://time.certum.pl");
    PdfOrdinarySignatureMaker signatureMaker = new PdfOrdinarySignatureMaker(doc, formatter);
    IPdfSignatureAppearance signatureAppearance = new PdfCustomSignatureAppearance();
    signatureMaker.MakeSignature("sign", doc.Pages[0], 100, 100, 100, 100, signatureAppearance);   
    doc.SaveToFile(outputFile, FileFormat.PDF);
    doc.Close();
}
public class PdfCustomSignatureAppearance : IPdfSignatureAppearance
{
    public void Generate(PdfCanvas g)
    {
float fontSize = 10;
PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", fontSize), true);
g.DrawString("AAAAAAAAAAA", font, PdfBrushes.Red, new PointF(0, 0));
    }
}

string url = "http://test1.tsa.cn/tsa";
signature.ConfigureTimestamp(url, "tsademo", "tsademo");

doc.LoadFromSvg(Stream stream);

sheet.GetColumnIsHide(columnIndex) 
sheet.GetRowIsHide(rowIndex) 

workbook.CustomFontFileDirectory = new string[] { "./Data/Font" };

Document doc = new Document();
Section section = doc.AddSection();
section.AddParagraph().AppendHorizonalLine();
doc.SaveToFile("result.docx", FileFormat.Docx);