js压缩图片base64长度

 var myCanvas=$('.img-container > img').cropper('getCroppedCanvas');

 (function (base64){

     var image = new Image(),newBase64,MAX_HEIGHT = 160;

     image.onload = function(){

         var canvas = document.getElementById("myCanvas");

         if(image.height > MAX_HEIGHT) {

             image.width *= MAX_HEIGHT / image.height;

             image.height = MAX_HEIGHT;

         }

         var ctx = canvas.getContext("2d");

         ctx.clearRect(0, 0, canvas.width, canvas.height);

         canvas.width = image.width;

         canvas.height = image.height;

         ctx.drawImage(image, 0, 0, image.width, image.height);

         newBase64=canvas.toDataURL('image/jpeg',0.4);
　　　　　　//上传base64编码

         $.ajax({

             type: "post",

             url: '地址',

             data: {

             },

             success: function (msg) {

                             },

             error: function (msg) {

                 tips.error('上传图片服务出错，请稍候再试。')

             }

         });

         console.log('base64Size',newBase64.length/1024);     };

     image.src = base64;

 })(myCanvas.toDataURL('image/jpeg'));

js压缩图片base64长度，不适于与高质量图片；

通过原base64编码在canvas中绘制新图片，并取出canvas使用toDataUrl方法得到新的base64；

绘制图片时通过改变原图片大小和toDataUrl中参数控制图片质量

js压缩图片base64长度的相关教程结束。