如何使用HTML5 canvas实现图像的马赛克

互联网 18-12-1

HTML5 canvas可以处理很多的图像问题，那么如何使用HTML5 canvas实现图像的马赛克呢？本篇文章就来给大家介绍HTML5 canvas实现图像的马赛克的方法，下面我们一起来看具体内容。

HTML5 canvas实现图像的马赛克代码如下

<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>     <title></title> 	<meta charset="utf-8" />   <script type="text/javascript">     var imageData;     function draw() {       var canvas = document.getElementById('SimpleCanvas');             var mem_canvas = document.createElement('canvas');             if (!canvas || !canvas.getContext) {               return false;       }             var context = canvas.getContext('2d');             var img = new Image();       img.onload = function onImageLoad() {         mem_canvas.width = img.width;         mem_canvas.height = img.height;               var mem_context = mem_canvas.getContext('2d');         mem_context.drawImage(img, 0, 0);          imageData = mem_context.getImageData(0, 0, mem_canvas.width, mem_canvas.height);         CreateMosaic(mem_context, mem_canvas.width, mem_canvas.height, 8);          context.drawImage(mem_canvas, 32, 32);       }       img.src = 'img/luffy.jpg';      }           function CreateMosaic(context, width,height,mosaicSize) {             var x=0;                   var y=0;                   for (y = 0; y < height; y = y + mosaicSize) {                     for (x = 0; x < width; x = x + mosaicSize) {                               var cR = imageData.data[(y * width + x) * 4];                               var cG = imageData.data[(y * width + x) * 4 + 1];                               var cB = imageData.data[(y * width + x) * 4 + 2];            context.fillStyle = "rgb("+cR+","+cG+","+cB+")";           context.fillRect(x, y, x + mosaicSize, y + mosaicSize);         }       }     }   </script> </head> <body onload="draw()" style="background-color:#D0D0D0;">   <canvas id="SimpleCanvas" width="640" height="360" style="background-color:#FFFFFF;"></canvas>   <div>Canvas Demo</div>   <div id="output"></div> </body> </html>

说明：

   function draw() {          var canvas = document.getElementById('SimpleCanvas');                var mem_canvas = document.createElement('canvas');       if (!canvas || !canvas.getContext) {                  return false;       }       var context = canvas.getContext('2d');       var img = new Image();       img.onload = function onImageLoad() {         mem_canvas.width = img.width;         mem_canvas.height = img.height;         var mem_context = mem_canvas.getContext('2d');         mem_context.drawImage(img, 0, 0);         imageData = mem_context.getImageData(0, 0, mem_canvas.width, mem_canvas.height);         CreateMosaic(mem_context, mem_canvas.width, mem_canvas.height, 8);         context.drawImage(mem_canvas, 32, 32);       }       img.src = 'img/luffy.jpg';      }

 function CreateMosaic(context, width,height,mosaicSize) {        var x=0;              var y=0;       for (y = 0; y < height; y = y + mosaicSize) {                for (x = 0; x < width; x = x + mosaicSize) {                     var cR = imageData.data[(y * width + x) * 4];                          var cG = imageData.data[(y * width + x) * 4 + 1];                          var cB = imageData.data[(y * width + x) * 4 + 2];           context.fillStyle = "rgb("+cR+","+cG+","+cB+")";           context.fillRect(x, y, x + mosaicSize, y + mosaicSize);         }       }     }

马赛克程度深浅的变化

CreateMosaic(mem_context, mem_canvas.width, mem_canvas.height, 8);

当第四个参数值为2时图像的马赛克效果

以上就是如何使用HTML5 canvas实现图像的马赛克的详细内容，更多内容请关注技术你好其它相关文章！

来源链接：

免责声明：
1.资讯内容不构成投资建议，投资者应独立决策并自行承担风险
2.本文版权归属原作所有，仅代表作者本人观点，不代表本站的观点或立场

标签： HTML5 canvas

如何使用HTML5 canvas实现图像的马赛克

相关资讯

标签推荐