pdf to tiff will loose the bold text

We are using Aspose.Pdf 7.0.0.0 for .NET to convert the attached pdf file into a tif file. The lines which are printed in bold in the pdf are no longer bold in the resulting tif. The trial of version 7.4.0.0 leads to the same result (please see the attached tif file).

Is there anything else we have to do in order to get the proper result?

            using (MemoryStreaminput=newMemoryStream(pdfData))

            {

               using (MemoryStreamoutput=newMemoryStream())

                {

                   PdfConverterpdfConverter=newPdfConverter();

                   pdfConverter.BindPdf(input);

                   pdfConverter.DoConvert();

                   pdfConverter.Resolution=newResolution(300);

                   pdfConverter.SaveAsTIFF(output,CompressionType.None);

                   pdfConverter.Close();

                   returnoutput.ToArray();

               }

            }