vue 上传图片显示不全

Question

前台使用base64编码格式，在后台数据库中取出就是这个样子

上传代码
compress(img){

  let canvas = document.createElement("canvas");
  let ctx = canvas.getContext("2d");
  //瓦片canvas
  let tCanvas = document.createElement("canvas");
  let tctx = tCanvas.getContext("2d");
  let initSize = img.src.length;

  let width = img.width;
  let height = img.height;
  //如果图片大于四百万像素，计算压缩比并将大小压至400万以下
  let ratio;
  if ((ratio = width * height / 4000000) > 1) {
    console.log("大于400万像素");
    ratio = Math.sqrt(ratio);
    width /= ratio;
    height /= ratio;
  } else {
    ratio = 1;
  }
  canvas.width = width;
  canvas.height = height;
  //        铺底色
  ctx.fillStyle = "#fff";
  ctx.fillRect(0, 0, canvas.width, canvas.height);
  //如果图片像素大于100万则使用瓦片绘制
  let count;
  if ((count = width * height / 1000000) > 1) {
    console.log("超过100W像素");
    count = ~~(Math.sqrt(count) + 1); //计算要分成多少块瓦片
    //            计算每块瓦片的宽和高
    let nw = ~~(width / count);
    let nh = ~~(height / count);
    tCanvas.width = nw;
    tCanvas.height = nh;
    for (let i = 0; i < count; i++) {
      for (let j = 0; j < count; j++) {
        tctx.drawImage(
          img,
          i * nw * ratio,
          j * nh * ratio,
          nw * ratio,
          nh * ratio,
          0,
          0,
          nw,
          nh
        );
        ctx.drawImage(tCanvas, i * nw, j * nh, nw, nh);
      }
    }
  } else {
    ctx.drawImage(img, 0, 0, width, height);
  }
  
  //进行最小压缩
  let ndata = canvas.toDataURL("image/jpeg", 0.1);
  console.log("压缩前：" + initSize);
  console.log("压缩后：" + ndata.length);
  console.log(
    "压缩率：" + ~~(100 * (initSize - ndata.length) / initSize) + "%"
  );
  tCanvas.width = tCanvas.height = canvas.width = canvas.height = 0;
  console.log(ndata);
  return ndata;
}

},