async getPixels({ type, data, width, height }) {
    if (type === 'raw') {
      return ndarray(data, [width, height, 4], [4, width * 4, 1]);
    } else {
      return await getPixelsFunc(data, `image/${type}`);
    }
  }
Get the pixel data of the image
https://github.com/stackgl/gl-texture2d/issues/16
@public