00001 // This is core/vnl/algo/vnl_fft_2d.h 00002 #ifndef vnl_fft_2d_h_ 00003 #define vnl_fft_2d_h_ 00004 #ifdef VCL_NEEDS_PRAGMA_INTERFACE 00005 #pragma interface 00006 #endif 00007 //: 00008 // \file 00009 // \brief In-place 2D fast Fourier transform 00010 // \author fsm 00011 00012 #include <vnl/vnl_matrix.h> 00013 #include <vnl/algo/vnl_fft_base.h> 00014 00015 //: In-place 2D fast Fourier transform 00016 00017 template <class T> 00018 struct vnl_fft_2d : public vnl_fft_base<2, T> 00019 { 00020 typedef vnl_fft_base<2, T> base; 00021 00022 //: constructor takes size of signal. 00023 vnl_fft_2d(int M, int N) { 00024 base::factors_[0].resize(M); 00025 base::factors_[1].resize(N); 00026 } 00027 00028 //: dir = +1/-1 according to direction of transform. 00029 void transform(vnl_matrix<vcl_complex<T> > &signal, int dir) 00030 { base::transform(signal.data_block(), dir); } 00031 00032 //: forward FFT 00033 void fwd_transform(vnl_matrix<vcl_complex<T> > &signal) 00034 { transform(signal, +1); } 00035 00036 //: backward (inverse) FFT 00037 void bwd_transform(vnl_matrix<vcl_complex<T> > &signal) 00038 { transform(signal, -1); } 00039 00040 //: return size of signal. 00041 unsigned rows() const { return base::factors_[0].number(); } 00042 unsigned cols() const { return base::factors_[1].number(); } 00043 }; 00044 00045 #endif // vnl_fft_2d_h_
1.7.5.1