var jpg : TJPEGImage;
...

      jpg:=TJPEGImage.Create;
      m:=TMemoryStream.Create;
     try
      TBlobField(Datasource2.DataSet.FieldByName('BILD1')).SaveToStream(m);
      m.Position:= 0;
      if m.Size > 0 then
      begin
        jpg.LoadFromStream(m);
        Image1.Picture.Assign(jpg);
      end else
      begin
        Image1.Picture := nil;
      end;
      finally
        FreeAndNil(m);
        FreeAndNil(jpg);
      end;