<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<canvas id="myCanvas" width="1000" height="500" >
Your browser does not support the HTML5 canvas tag.
</canvas>
<script>
//准备img对象
var img = new Image();
img.src = './img/demo.jpg';
// 加载完成开始绘制
img.onload=function(){
//准备canvas环境
var canvas=document.getElementById("myCanvas");
var ctx=canvas.getContext("2d");
// 绘制图片
ctx.drawImage(img,0,0);
// 绘制水印
ctx.font="20px microsoft yahei";
ctx.fillStyle = "rgba(255,255,255,0.5)";
ctx.fillText("my images",100,100);
}
</script>
</body>
其实就是