mui中调用相机照相后的图片路径怎样转换为file对象呢

function getImgToBase64 (url, callback) {
var that = this;
//将图片转换为Base64
//url 图片链接或者是blob对象
//callback 回调函数
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
var img = new Image;
img.onload = function () {
canvas.height = img.height ;
canvas.width = img.width ;
ctx.drawImage(img, 0, 0); //将图片绘制到canvas中
var dataURL = canvas.toDataURL('image/png'); //转换图片为dataURL,传第二个参数可压缩图片,前提是图片格式jpeg或者webp格式的
callback(dataURL); //调用回调函数
canvas = null;
};
img.src = url;
}
// //将base64转换为文件对象
function dataURLtoFile (dataurl, filename) {
var that = this;
var arr = dataurl.split(',');
var mime = arr[0].match(/:(.*?);/)[1];
var bstr = atob(arr[1]);
var n = bstr.length;
var u8arr = new Uint8Array(n);
while (n--) {
u8arr[n] = bstr.charCodeAt(n);
}
//转换成file对象
return new File([u8arr], filename, {
type: mime
});
}

getImgToBase64('url', function (data) {
var myFile = that.dataURLtoFile(data, 'name');

                    });