canvas图片跨域怎么解决

Question

在把canvas画出来的图转成图片是报下面的错：Uncaught DOMException: Failed to execute 'toDataURL' on 'HTMLCanvasElement': Tainted canvases may not be exported.应该是跨域的问题吧；加上：image.setAttribute('crossOrigin', 'anonymous');也没用，要怎么解决的好嘞？