ncnn：提取所有层特征值

官方代码托管地址：https://github.com/Tencent/ncnn

在Extractor类中添加以下方法：

int Extractor::extract_all_blobs()
{
    for (int blob_index = 0; blob_index < blob_mats.size(); blob_index++)
    {
      Mat outMat;
      extract(blob_index, outMat);

      // write to file
      char path[256];
      char id[8];

      strcpy(path, "./ncnn_blobs_data/");
      sprintf(id, "%d", blob_index);
      strcat(path, id);
      strcat(path, ".txt");

      FILE *fp = fopen(path, "w+");
      if(!fp)
        fprintf(stderr, "error open file
");

      // header
      fprintf(fp, net->blobs[blob_index].name.c_str());
      fprintf(fp, "
");

      for (int idx = 0; idx < outMat.w * outMat.h * outMat.c; idx++)
        fprintf(fp, "%f
", outMat[idx]);
      fclose(fp);
    }

    return 0;
}