LBPH预测函数源码

void LBPH::predict(InputArray _src, int &minClass, double &minDist) const {
    if(_histograms.empty()) {
        // throw error if no data (or simply return -1?)
        string error_message = "This LBPH model is not computed yet. Did you call the train method?";
        CV_Error(CV_StsBadArg, error_message);
    }
    Mat src = _src.getMat();
    // get the spatial histogram from input image
    Mat lbp_image = elbp(src, _radius, _neighbors);
    Mat query = spatial_histogram(
            lbp_image, /* lbp_image */
            static_cast(std::pow(2.0, static_cast(_neighbors))), /* number of possible patterns */
            _grid_x, /* grid size x */
            _grid_y, /* grid size y */
            true /* normed histograms */);
    // find 1-nearest neighbor
    minDist = DBL_MAX;
    minClass = -1;
    for(size_t sampleIdx = 0; sampleIdx < _histograms.size(); sampleIdx++) {
        double dist = compareHist(_histograms[sampleIdx], query, CV_COMP_CHISQR);
        if((dist < minDist) && (dist < _threshold)) {
            minDist = dist;
            minClass = _labels.at((int) sampleIdx);
        }
    }
}