Muy Buenas noches, mi duda es como puedo poner imágenes en esta ruleta en vez de letras este es el código:
<input id="boton" type="button" onclick="spin()"; onmouseOver="alert
 
('EVENTO CERRADO')"/><img src="imagen/boton.png"/>
              <canvas id="wheelcanvas" width="500" height="500"></canvas>
              <script type="application/javascript">
                var colors = ["#4B459B", "#848484", "#9B9B45", "#FFFF00",
                             "#FF4000", "#FF0000", "#8000FF", "#0000FF"];
                var ruleta = ["PERDISTE", "SORPRESA", "PERDISTE", "GANASTE",
                                   "PERDISTE", "GANASTE", "PERDISTE", "GANASTE"];
 
                var startAngle = 0;
                var arc = Math.PI / 4;
                var spinTimeout = null;
 
                var spinArcStart = 20;
                var spinTime = 0;
                var spinTimeTotal = 0;
 
                var ctx;
 
                function draw() {
                  drawRouletteWheel();
                }
 
                function drawRouletteWheel() {
                  var canvas = document.getElementById("wheelcanvas");
                  if (canvas.getContext) {
                    var outsideRadius = 248;
                    var textRadius = 190;
                    var insideRadius = 120;
 
                    ctx = canvas.getContext("2d");
                    ctx.clearRect(0,0,500,500);
 
 
                    ctx.strokeStyle = "#00090B";
                    ctx.lineWidth = 2;
 
                    ctx.font = 'bold 20px sans-serif';
 
                    for(var i = 0; i < 8; i++) {
                      var angle = startAngle + i * arc;
                      ctx.fillStyle = colors[i];
 
                      ctx.beginPath();
                      ctx.arc(250, 250, outsideRadius, angle, angle + arc, false);
                      ctx.arc(250, 250, insideRadius, angle + arc, angle, true);
                      ctx.stroke();
                      ctx.fill();
 
                      ctx.save();
                      ctx.shadowOffsetX = -1;
                      ctx.shadowOffsetY = -1;
                      ctx.shadowBlur    = 0;
                      ctx.shadowColor   = "rgb(220,220,220)";
                      ctx.fillStyle = "#00090B";
                      ctx.translate(250 + Math.cos(angle + arc / 2) * textRadius, 
 
250 + Math.sin(angle + arc / 2) * textRadius);
                      ctx.rotate(angle + arc / 2 + Math.PI / 2);
                      var text = ruleta[i];
                      ctx.fillText(text, -ctx.measureText(text).width / 2, 0);
                      ctx.restore();
                    } 
 
                    //Arrow
                    ctx.fillStyle = "#00090B";
                    ctx.beginPath();
                    ctx.moveTo(250 - 7, 250 - (outsideRadius + 8));
                    ctx.lineTo(250 + 7, 250 - (outsideRadius + 8));
                    ctx.lineTo(250 + 7, 250 - (outsideRadius - 8));
                    ctx.lineTo(250 + 13, 250 - (outsideRadius - 8));
                    ctx.lineTo(250 + 0, 250 - (outsideRadius - 18));
                    ctx.lineTo(250 - 13, 250 - (outsideRadius - 8));
                    ctx.lineTo(250 - 7, 250 - (outsideRadius - 8));
                    ctx.lineTo(250 - 7, 250 - (outsideRadius + 8));
                    ctx.fill();
                  }
                }
 
                function spin() {
                  spinAngleStart = Math.random() * 10 + 10;
                  spinTime = 0;
                  spinTimeTotal = Math.random() * 3 + 4 * 1000;
                  rotateWheel();
                }
 
                function rotateWheel() {
                  spinTime += 30;
                  if(spinTime >= spinTimeTotal) {
                    stopRotateWheel();
                    return;
                  }
                  var spinAngle = spinAngleStart - easeOut(spinTime, 0, 
 
spinAngleStart, spinTimeTotal);
                  startAngle += (spinAngle * Math.PI / 180);
                  drawRouletteWheel();
                  spinTimeout = setTimeout('rotateWheel()', 30);
                }
 
                function stopRotateWheel() {
                  clearTimeout(spinTimeout);
                  var degrees = startAngle * 180 / Math.PI + 90;
                  var arcd = arc * 180 / Math.PI;
                  var index = Math.floor((360 - degrees % 360) / arcd);
                  ctx.save();
                  ctx.font = 'bold 20px sans-serif';
                  var text = ruleta[index]
                  ctx.fillText(text, 250 - ctx.measureText(text).width / 2, 250 + 
 
10);
                  ctx.restore();
                }
 
                function easeOut(t, b, c, d) {
                  var ts = (t/=d)*t;
                  var tc = ts*t;
                  return b+c*(tc + -3*ts + 3*t);
                }
 
                draw();
              </script> 
  
 

