<canvas id ="cvs20" width ="400" height = "400">
      votre navigateur n'accepte pas Canvas
</canvas>
<script>
   var canv1 = document.getElementById('cvs20');
     var context1 = canv1.getContext('2d');
     var image1 = new Image();
   image1.src = 'img/lyon.jpg'; //adresse de l'image
   image1.onload = function () {
                          var repet1 = context1.createPattern(this,'repeat');
                           context1.fillStyle = repet1;
                           context1.fillRect(0,0,cvs20.width, cvs20.height);
                            }
   </script>