+ static const char FILTER_METHOD_CONVOLUTION_STR[]= "convolution";
+ static const char FILTER_METHOD_FOURIER_STR[]= "fourier";
+ static const char FILTER_METHOD_FFT_STR[]= "fft";
+ static const char FILTER_METHOD_FFT_ZEROPAD_2_STR[]="fft_zeropad2";
+ static const char FILTER_METHOD_FFT_ZEROPAD_4_STR[]="fft_zeropad4";
+ static const char FILTER_METHOD_FFT_ZEROPAD_6_STR[]="fft_zeropad6";
+