Base64 to Blob Javascript + Check Size base64 Javascript

1.    const b64toBlob = (b64Data, contentType='', sliceSize=512) => {

  const byteCharacters = atob(b64Data);

  const byteArrays = [];

  for (let offset = 0; offset < byteCharacters.length; offset += sliceSize) {

    const slice = byteCharacters.slice(offset, offset + sliceSize);

    const byteNumbers = new Array(slice.length);

    for (let i = 0; i < slice.length; i++) {

      byteNumbers[i] = slice.charCodeAt(i);

    }

    const byteArray = new Uint8Array(byteNumbers);

    byteArrays.push(byteArray);

  }

  const blob = new Blob(byteArrays, {type: contentType});

  return blob;

}

            " call functional => b64toBlob(b64Data,contentType) "

2. Check size base64 with javascript (Kilo Byte)

            function calc_image_size(image) {

    let y = 1;

    if (image.endsWith('==')) {

        y = 2

    }

    const x_size = (image.length * (3 / 4)) - y

    return Math.round(x_size / 1024)

}

    " call functional => calc_image_size(b64Data) "