[[ElDioni]]

gracias por responder tan pronto he probado el cast:

Código Delphi [-]
procedure TFrmDibujo.Button1Click(Sender: TObject);
var
  jp: TJPEGImage;  //Requires the "jpeg" unit added to "uses" clause.
begin
  jp := TJPEGImage.Create;
  jp.LoadFromFile(frmdibujo.caption);
  try
    printer.BeginDoc;
    printer.canvas.Draw(0,0,tgraphic(jp));
    printer.EndDoc;
  finally
    jp.free;
  end;
end;

y me suelta lo siguiente:

[Error] Unit2.pas(38): Incompatible types: 'QGraphics.TGraphic' and 'Graphics.TGraphic'