// Copyright (C) 2011 Davis E. King (davis@dlib.net) // License: Boost Software License See LICENSE.txt for the full license. #ifndef DLIB_BUILD_SEPARABLE_PoLY_FILTERS_Hh_ #define DLIB_BUILD_SEPARABLE_PoLY_FILTERS_Hh_ #include "../matrix.h" #include "surf.h" #include "../uintn.h" #include <vector> namespace dlib { // ---------------------------------------------------------------------------------------- typedef std::pair<matrix<double,0,1>, matrix<double,0,1> > separable_filter_type; typedef std::pair<matrix<int32,0,1>, matrix<int32,0,1> > separable_int32_filter_type; // ---------------------------------------------------------------------------------------- inline std::vector<std::vector<separable_filter_type> > build_separable_poly_filters ( const long order, const long window_size ) /*! requires - 1 <= order <= 6 - window_size >= 3 && window_size is odd ensures - the "first" element is the row_filter, the second is the col_filter. - Some filters are not totally separable and that's why they are grouped into vectors of vectors. The groups are all the parts of a partially separable filter. !*/ { long num_filters = 6; switch (order) { case 1: num_filters = 3; break; case 2: num_filters = 6; break; case 3: num_filters = 10; break; case 4: num_filters = 15; break; case 5: num_filters = 21; break; case 6: num_filters = 28; break; } matrix<double> X(window_size*window_size,num_filters); matrix<double,0,1> G(window_size*window_size,1); const double sigma = window_size/4.0; long cnt = 0; for (double x = -window_size/2; x <= window_size/2; ++x) { for (double y = -window_size/2; y <= window_size/2; ++y) { X(cnt, 0) = 1; X(cnt, 1) = x; X(cnt, 2) = y; if (X.nc() > 5) { X(cnt, 3) = x*x; X(cnt, 4) = x*y; X(cnt, 5) = y*y; } if (X.nc() > 9) { X(cnt, 6) = x*x*x; X(cnt, 7) = y*x*x; X(cnt, 8) = y*y*x; X(cnt, 9) = y*y*y; } if (X.nc() > 14) { X(cnt, 10) = x*x*x*x; X(cnt, 11) = y*x*x*x; X(cnt, 12) = y*y*x*x; X(cnt, 13) = y*y*y*x; X(cnt, 14) = y*y*y*y; } if (X.nc() > 20) { X(cnt, 15) = x*x*x*x*x; X(cnt, 16) = y*x*x*x*x; X(cnt, 17) = y*y*x*x*x; X(cnt, 18) = y*y*y*x*x; X(cnt, 19) = y*y*y*y*x; X(cnt, 20) = y*y*y*y*y; } if (X.nc() > 27) { X(cnt, 21) = x*x*x*x*x*x; X(cnt, 22) = y*x*x*x*x*x; X(cnt, 23) = y*y*x*x*x*x; X(cnt, 24) = y*y*y*x*x*x; X(cnt, 25) = y*y*y*y*x*x; X(cnt, 26) = y*y*y*y*y*x; X(cnt, 27) = y*y*y*y*y*y; } G(cnt) = std::sqrt(gaussian(x,y,sigma)); ++cnt; } } X = diagm(G)*X; const matrix<double> S = inv(trans(X)*X)*trans(X)*diagm(G); matrix<double,0,1> row_filter, col_filter; matrix<double> u,v, temp; matrix<double,0,1> w; std::vector<std::vector<separable_filter_type> > results(num_filters); for (long r = 0; r < S.nr(); ++r) { temp = reshape(rowm(S,r), window_size, window_size); svd3(temp,u,w,v); const double thresh = max(w)*1e-8; for (long i = 0; i < w.size(); ++i) { if (w(i) > thresh) { col_filter = std::sqrt(w(i))*colm(u,i); row_filter = std::sqrt(w(i))*colm(v,i); results[r].push_back(std::make_pair(row_filter, col_filter)); } } } return results; } // ---------------------------------------------------------------------------------------- inline std::vector<std::vector<separable_int32_filter_type> > build_separable_int32_poly_filters ( const long order, const long window_size, const double max_range = 300.0 ) /*! requires - 1 <= order <= 6 - window_size >= 3 && window_size is odd - max_range > 1 ensures - the "first" element is the row_filter, the second is the col_filter. !*/ { const std::vector<std::vector<separable_filter_type> >& filters = build_separable_poly_filters(order, window_size); std::vector<std::vector<separable_int32_filter_type> > int_filters(filters.size()); for (unsigned long i = 0; i < filters.size(); ++i) { double max_val = 0; for (unsigned long j = 0; j < filters[i].size(); ++j) { const separable_filter_type& filt = filters[i][j]; max_val = std::max(max_val, max(abs(filt.first))); max_val = std::max(max_val, max(abs(filt.second))); } if (max_val == 0) max_val = 1; int_filters[i].resize(filters[i].size()); for (unsigned long j = 0; j < filters[i].size(); ++j) { const separable_filter_type& filt = filters[i][j]; int_filters[i][j].first = matrix_cast<int32>(round(filt.first*max_range/max_val)); int_filters[i][j].second = matrix_cast<int32>(round(filt.second*max_range/max_val)); } } return int_filters; } } // ---------------------------------------------------------------------------------------- #endif // DLIB_BUILD_SEPARABLE_PoLY_FILTERS_Hh_