JS——图片转base码 、base转File对象

【图片转base码】

function imgToBase(url){
    
    let img = document.createElement("img")
    img.src = url
    img.setAttribute("crossOrigin",'Anonymous')
    let canvas = document.createElement("canvas");
    canvas.width = img.width;
    canvas.height = img.height;
    let ctx = canvas.getContext("2d");
    ctx.drawImage(img, 0, 0, img.width, img.height);
    return canvas.toDataURL();
 }
  
//调用
imgToBase("https://img1.baidu.com/it/u=3382370226,1921570240&fm=253&fmt=auto&app=138&f=JPEG?w=800&h=320")

【base码转File对象】

//base-base码
//name-文件名
function baseToFile(base, name) {
    
    var arr = base.split(','),
      mime = arr[0].match(/:(.*?);/)[1],
      bstr = atob(arr[1]),
      n = bstr.length,
      u8arr = new Uint8Array(n)
    while (n--) {
    
      u8arr[n] = bstr.charCodeAt(n)
    }
    return new File([u8arr], name, {
    
      type: mime,
    })
  }
//调用
baseToFile(base,"fileName.jpg")