Zxing iOS：裁剪BinaryBitMap

Question

我正在尝试同时读取3个条形码，因此我需要将图像分成3个部分。我尝试了这个，但它失败了：

Ref<Result> MultiFormatReader::decodeInternal(Ref<BinaryBitmap> image){
   try{
      DecodeHints hints = DecodeHints::DEFAULT_HINT;
      oned::MultiFormatOneDReader od(hints);
      image->crop(0,0,100,image->getHeight()); //This method is not implemented, I don't know why.
      return od.decode(image, hints);
   } catch (ReaderException const& re){
      (void)re;
   }
   throw ReaderException("No code detected");

有人有想法吗？

谢谢！