Create DBGrid that shows images

First of all set DefaultDrawing flag of the DBGrid to the False. Then add the following code to the DBGrid's OnDrawColumnCell event:

procedure TForm1.DBGrid1DrawDataCell(Sender: TObject; const Rect: TRect;
  Field: TField; State: TGridDrawState);
var
  Bmp: TBitmap;
begin
  if Field is TGraphicField then
  begin
    try
      Bmp:=TBitmap.Create;
      Bmp.Assign(Field);
      DBGrid1.Canvas.StretchDraw(Rect, Bmp);
    finally
      Bmp.Free;
    end
  end
  else
    DBGrid1.DefaultDrawDataCell(Rect, Field, State);
end;