在JS中将ImageData转换为blob？

var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');

ctx.putImageData(imageData, 0, 0);

var dataURL = canvas.toDataURL();

function dataURLtoBlob(dataURL) {
  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);
  }
  return new Blob([u8arr], { type: mime });
}

var blob = dataURLtoBlob(dataURL);