如何将图片base64字符串转PixelMap？

import { util } from '@kit.ArkTS';
import { image } from '@kit.ImageKit';

 base64ToPixelMap(base64: string): Promise<image.PixelMap> {
  //将原始图片base64字符串转变为通过base64字符串
  const reg = new RegExp('data:image/\\w+;base64,');
  const base64Str = base64.replace(reg, '');
  //将通用base64字符串转变为arrayBuffer
  let base64Helper = new util.Base64Helper();
  let arrayBuffer = base64Helper.decodeSync(base64Str).buffer as ArrayBuffer;
  //将arrayBuffer转变为pixelMap
  let imageSource = image.createImageSource(arrayBuffer);
  let opts: image.DecodingOptions = { editable: false }
  //注意：这里return的是Promise，因此使用时需要在业务侧拿到最终的PixelMap
  return imageSource.createPixelMap(opts);
}