//this method demonstrates how to create a PDF/A-1b compliant 
//document from a compressed image of a Document
public void saveImageAsPDFa(string imageFileName, 
                            Document targetDocument, 
                           string iccFileName)
{
    PageOptions targetPageOptions = new PageOptions();
    //using standard page size
    targetPageOptions.MediaHeight = 72.0 * 11;
    targetPageOptions.MediaWidth = 72.0 * 8.5;
    targetDocument.CreatePage(-1, targetPageOptions);
    targetDocument.AddImage(0, 0, 0, targetPageOptions.MediaWidth, 
                            targetPageOptions.MediaHeight, ImageFitSettings.Shrink, 
                            imageFileName, 0);
    ConvertOptions convertOpts = new ConvertOptions();
    //specify a valid ICC profile to embed
    convertOpts.IccProfileFilename = iccFileName;
    convertOpts.PdfType = PdfType.pdfA1b;
    //convert the target document to PDF/A-1b
    try
    {
        targetDocument.ConvertToPdfA(convertOpts);
    }
    catch (PdfXpressException pdfXexception)
    {
        //an error occurred in conversion
    }
    //save the converted PDF/A-1b document
    Accusoft.PdfXpressSdk.SaveOptions saveOpts = new Accusoft.PdfXpressSdk.SaveOptions();
    saveOpts.Filename = "imagePDFa.pdf";
    targetDocument.Save(saveOpts);
}