void HOGFeatures<T>::pyramid(const Mat& im, vectorMat& pyrafeatures) {

	// calculate the scaling factor
	Size_<float> imsize = im.size();
	nscales_  = 1 + floor(log(min(imsize.height, imsize.width)/(5.0f*(float)binsize_))/log(sfactor_));

	vectorMat pyraimages;
	pyraimages.resize(nscales_);
	pyrafeatures.clear();
	pyrafeatures.resize(nscales_);
	pyraimages.resize(nscales_);
	scales_.clear();
	scales_.resize(nscales_);

	// perform the non-power of two scaling
	// TODO: is this the most intuitive way to represent scaling?
	#ifdef _OPENMP
	#pragma omp parallel for
	#endif
	for (unsigned int i = 0; i < interval_; ++i) {
		Mat scaled;
		resize(im, scaled, imsize * (1.0f/pow(sfactor_,(int)i)));
		pyraimages[i] = scaled;
		scales_[i] = pow(sfactor_,(int)i)*binsize_;
		// perform subsequent power of two scaling
		for (unsigned int j = i+interval_; j < nscales_; j+=interval_) {
			Mat scaled2;
			pyrDown(scaled, scaled2);
			pyraimages[j] = scaled2;
			scales_[j] = 2 * scales_[j-interval_];
			scaled2.copyTo(scaled);
		}
	}

	// perform the actual feature computation, in parallel if possible
	#ifdef _OPENMP
	#pragma omp parallel for
	#endif
	for (unsigned int n = 0; n < nscales_; ++n) {
		Mat feature;
		Mat padded;
		switch (im.depth()) {
			case CV_32F: features<float>(pyraimages[n], feature); break;
			case CV_64F: features<double>(pyraimages[n], feature); break;
			case CV_8U:  features<uint8_t>(pyraimages[n], feature); break;
			case CV_16U: features<uint16_t>(pyraimages[n], feature); break;
			default: CV_Error(cv::Error::StsUnsupportedFormat, "Unsupported image type"); break;
		}
		//copyMakeBorder(feature, padded, 3, 3, 3*flen_, 3*flen_, BORDER_CONSTANT, 0);
		//boundaryOcclusionFeature(padded, flen_, 3);
		pyrafeatures[n] = feature;
	}
}
	/*! @brief return the filters for all mixtures of a part
	 *
	 * @param out the filters to return
	 */
	void filters(vectorMat& out) const {
		out.clear();
		for (unsigned int m = 0; m < filterid_[self_].size(); ++m) {
			out.push_back((*filtersw_)[(*filterid_)[self_][m]]);
		}
	}