worker的js代码img.js
onmessage = function(e) { postMessage(filter(e.data)) }; function filter(imgd) { var pix = imgd.pixels.data; var xcord = imgd.x / 1000; var ycord = imgd.y / 1000; for ( var i = 0, n = pix.length; i < n; i += 4) { var grayscale = pix[i] * xcord + pix[i + 1] * .59 + pix[i + 2] * .11; pix[i] = grayscale; // red pix[i + 1] = grayscale; // green pix[i + 2] = grayscale; // blue } imgd['pixels'].data = pix; return imgd; }
html代码
<!DOCTYPE html> <html> <head> <title>test2.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> <script type="text/javascript" src="../js/jquery-1.8.0.min.js"></script> </head> <body> <canvas id="myCanvas" width="640" height="480"></canvas> <img src="../image/psu[4].jpg" class="onHover"> //注意,自己在这里插入一张图片,否则没用效果 <script type="text/javascript"> function process(img,x,y){ var canvas = document.getElementById("myCanvas"); var context = canvas.getContext('2d'); context.drawImage(img, 0, 0); var pixels = context.getImageData(0,0,img.width,img.height); var worker = new Worker("img.js"); var obj = { pixels: pixels, x:x, y:y } worker.postMessage(obj); worker.onmessage = function(e) { if (typeof e.data === "string") { console.log("Worker: " + e.data); return; } var new_pixels = e.data.pixels; // Pixels from worker context.putImageData(new_pixels, 0, 0); img.src = canvas.toDataURL(); // And then to the img } } </script> <script type="text/javascript"> $(function(){ $(".onHover").on("mouseover", function(){ var x =this.width; var y = this.height; console.log("X: " + x + " Y: " + y); process(this, x, y); }); }) </script> </body> </html>
是执行上面的例子的时候 ,要自己引入jquery包,并且在html页面上的img标签上放入自己要变换的图片。然后部署到服务器,打开页面,当鼠标移动到图片的 上面的时候就会发生变换,在这里执行变换功能的函数有worker负责,随意不影响页面本身的效率,类似于java语言中的多线程。
以上就是html5 worker 实例(二) 图片变换效果的内容,更多相关内容请关注PHP中文网(m.sbmmt.com)!
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