Imprimir HTML 2 Canvas

$(function() {
          $("#crearimagen").click(function() {
              html2canvas($("#contenido"), {
                onrendered: function(canvas) {
                    var myImage = canvas.toDataURL("image/png");
                    var tWindow = window.open("");
                    $(tWindow.document.body)
                        .html("<img id='Image' src=" + myImage + " style='width:100%;'></img>")
                        .ready(function() {
                            tWindow.focus();
                            tWindow.print();
                        });
                }
            });
          });
      });