原生JS操作图片汇总

获取图片真实尺寸

根据图片地址，获取该图片的实际宽度和高度

let img = new Image()
img.src = 'https://www.baidu.com/img/bd_logo1.png?qua=high'
img.onload = function() {
  let nWidth = img.naturalWidth;
  let nHeight = img.naturalHeight;
  console.log(nWidth, nHeight)
}

文件转成二进制

使用input['file']等获取的文件DataURI，将其转成二进制数据

function convertDataURIToBinary(dataURI) {
  var BASE64_MARKER = ';base64,';
  var base64Index = dataURI.indexOf(BASE64_MARKER) + BASE64_MARKER.length;
  var base64 = dataURI.substring(base64Index);
  var raw = window.atob(base64);
  var rawLength = raw.length;
  var array = new Uint8Array(new ArrayBuffer(rawLength));

  for (let i = 0; i < rawLength; i++) {
    array[i] = raw.charCodeAt(i);
  }
  return array;
}