IsSigned example for Delphi
{Load the bitmap data as signed so we can use a different conversion}
LEADImage1.LoadSigned := True;
LEADImage1.Load ('c:\temp\signed.tif', 0, 0, 1);
{ use the non-default conversion "zero to center"}
LEADImage1.ConvertSignedToUnsigned (SHIFT_ZERO_TO_CENTER);