lo solucione cuando grabo :
Código Delphi
[-]var
ftblob : tblobtype;
begin
zquery1.Active;
zquery1.close;
zquery1.SQL.Clear;
zquery1.sql.add ('insert into xxx (..., ..., digital)');
zquery1.sql.add ('values..,... :digital)');
zquery1.Params.ParamByName('....').Value := 'Documento';
zquery1.Params.ParamByName('...').Value := 'kk';
zquery1.Params.ParamByName('digital').LoadFromFile('c:\foto.jpg',
ftblob);
zquery1.Active;
zquery1.ExecSQL;
cuando traigo los datos
Código Delphi
[-]var
ftblob : Tblobfield;
jpg : TJpegImage ;
begin
zquery1.Active;
zquery1.close;
zquery1.SQL.Clear;
zquery1.sql.add ('select digital from ....');
zquery1.sql.add ('where codigo = 1');
zquery1.Active := True;
zquery1.Open ;
ftblob := zQuery1.FieldByName('digital') as TBlobField;
jpg:= TJpegImage.Create;
jpg.Assign(ftblob);
image1.Picture.Graphic:=jpg;