Comparing fingerprint live capture and template from DB

Question

I'm stuck here when I try to compare the data from database to the live capture from the reader. The fingerprint is saved as image in the database.

I think I made a mistake here.

int conversionFormat = Convert.ToInt32(Constants.Formats.Fmd.ANSI);
Fmd fThumb = new Fmd((byte[])dr["FPThumb"], conversionFormat, Constants.WRAPPER_VERSION);

CompareResult compareResult = Comparison.Compare(anyFinger, 0, fThumb, 0);

When I try to compare the obj it gives me an error.

if (compareResult.ResultCode != Constants.ResultCode.DP_SUCCESS)
{
   _sender.Reset = true;
   throw new Exception(compareResult.ResultCode.ToString());}

I think my mistake here is that when I convert the data from the database and I have no idea how.