解决阿里云 oss存储 canvas 画图跨源污染问题

项目有一个类似美图秀秀的功能，存放在本地时能对图片正常编辑，考虑到图片量大，用了阿里云oss

但是出现了错误：Uncaught DOMException: Failed to execute 'getImageData' on 'CanvasRenderingContext2D': The canvas has been tainted by cross-origin data.at Image.img.onload

于是百度查阅资料，太多同类文章，有需要还是上Google好些

解决方法：

var timestamp =new Date().getTime();
img.setAttribute('crossOrigin', 'anonymous');
img.src = url +'?' + timestamp;

参考：https://stackoverflow.com/questions/20424279/canvas-todataurl-securityerror/27260385#27260385