X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=f86478653bbf4d93a814c66a51db717b93d289be;hp=4ac901786c29a9b274cf75d589491dfd24c2046a;hb=9776c9a12ba53419d34563a5ec57c90e3d6798f4;hpb=9f29c8b32c972db1178d6f8551d5cd57ceb67083 diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp index 4ac9017..f864786 100644 --- a/libctsim/filter.cpp +++ b/libctsim/filter.cpp @@ -9,7 +9,7 @@ ** This is part of the CTSim program ** Copyright (c) 1983-2000 Kevin Rosenberg ** -** $Id: filter.cpp,v 1.35 2001/01/28 19:10:18 kevin Exp $ +** $Id: filter.cpp,v 1.38 2001/02/22 18:22:40 kevin Exp $ ** ** This program is free software; you can redistribute it and/or modify ** it under the terms of the GNU General Public License (version 2) as @@ -30,39 +30,47 @@ int SignalFilter::N_INTEGRAL=500; //static member const int SignalFilter::FILTER_INVALID = -1 ; -const int SignalFilter::FILTER_ABS_BANDLIMIT = 0; // filter times |x = | +const int SignalFilter::FILTER_ABS_BANDLIMIT = 0; // filter times |x| const int SignalFilter::FILTER_ABS_G_HAMMING = 1; -const int SignalFilter::FILTER_ABS_COSINE = 2; -const int SignalFilter::FILTER_ABS_SINC = 3; -const int SignalFilter::FILTER_SHEPP = 4; -const int SignalFilter::FILTER_BANDLIMIT = 5; -const int SignalFilter::FILTER_SINC = 6; -const int SignalFilter::FILTER_G_HAMMING = 7; -const int SignalFilter::FILTER_COSINE = 8; -const int SignalFilter::FILTER_TRIANGLE = 9; - -const char* SignalFilter::s_aszFilterName[] = { +const int SignalFilter::FILTER_ABS_HANNING = 2; +const int SignalFilter::FILTER_ABS_COSINE = 3; +const int SignalFilter::FILTER_ABS_SINC = 4; +const int SignalFilter::FILTER_SHEPP = 5; +const int SignalFilter::FILTER_BANDLIMIT = 6; +const int SignalFilter::FILTER_SINC = 7; +const int SignalFilter::FILTER_G_HAMMING = 8; +const int SignalFilter::FILTER_HANNING = 9; +const int SignalFilter::FILTER_COSINE = 10; +const int SignalFilter::FILTER_TRIANGLE = 11; + +const int SignalFilter::s_iReconstructFilterCount = 4; + +const char* const SignalFilter::s_aszFilterName[] = { {"abs_bandlimit"}, {"abs_hamming"}, + {"abs_hanning"}, {"abs_cosine"}, - {"abs_sinc"}, {"shepp"}, + {"abs_sinc"}, {"bandlimit"}, {"sinc"}, {"hamming"}, + {"hanning"}, {"cosine"}, {"triangle"}, }; -const char* SignalFilter::s_aszFilterTitle[] = { +const char* const SignalFilter::s_aszFilterTitle[] = { {"Abs(w) * Bandlimit"}, {"Abs(w) * Hamming"}, + {"Abs(w) * Hanning"}, {"Abs(w) * Cosine"}, - {"Abs(w) * Sinc"}, {"Shepp"}, + {"Abs(w) * Sinc"}, {"Bandlimit"}, {"Sinc"}, {"Hamming"}, + {"Hanning"}, {"Cosine"}, {"Triangle"}, }; @@ -74,12 +82,12 @@ const int SignalFilter::DOMAIN_INVALID = -1; const int SignalFilter::DOMAIN_FREQUENCY = 0; const int SignalFilter::DOMAIN_SPATIAL = 1; -const char* SignalFilter::s_aszDomainName[] = { +const char* const SignalFilter::s_aszDomainName[] = { {"frequency"}, {"spatial"}, }; -const char* SignalFilter::s_aszDomainTitle[] = { +const char* const SignalFilter::s_aszDomainTitle[] = { {"Frequency"}, {"Spatial"}, }; @@ -437,12 +445,18 @@ SignalFilter::frequencyResponse (int filterID, double bw, double u, double param case FILTER_ABS_SINC: q = au * bw * sinc (PI * bw * u, 1.); break; + case FILTER_HANNING: + param = 0.54; + // follow through to G_HAMMING case FILTER_G_HAMMING: if (fabs(au) >= fabs(bw / 2) + F_EPSILON) q = 0; else q = param + (1 - param) * cos (TWOPI * u / bw); break; + case FILTER_ABS_HANNING: + param = 0.54; + // follow through to ABS_G_HAMMING case FILTER_ABS_G_HAMMING: if (fabs(au) >= fabs(bw / 2) + F_EPSILON) q = 0; @@ -489,9 +503,11 @@ SignalFilter::haveAnalyticSpatial (int filterID) case FILTER_TRIANGLE: case FILTER_COSINE: case FILTER_G_HAMMING: + case FILTER_HANNING: case FILTER_ABS_BANDLIMIT: case FILTER_ABS_COSINE: case FILTER_ABS_G_HAMMING: + case FILTER_ABS_HANNING: case FILTER_SHEPP: case FILTER_SINC: haveAnalytic = true; @@ -523,6 +539,9 @@ SignalFilter::spatialResponseAnalytic (int filterID, double bw, double x, double case FILTER_COSINE: q = sinc(b-u,w) + sinc(b+u,w); break; + case FILTER_HANNING: + param = 0.54; + // follow through to G_HAMMING case FILTER_G_HAMMING: q = 2 * param * sin(u*w)/u + (1-param) * (sinc(b2-u, w) + sinc(b2+u, w)); break; @@ -532,6 +551,9 @@ SignalFilter::spatialResponseAnalytic (int filterID, double bw, double x, double case FILTER_ABS_COSINE: q = integral_abscos(b-u,w) + integral_abscos(b+u,w); break; + case FILTER_ABS_HANNING: + param = 0.54; + // follow through to ABS_G_HAMMING case FILTER_ABS_G_HAMMING: q = 2 * param * integral_abscos(u,w) + (1-param)*(integral_abscos(u-b2,w)+integral_abscos(u+b2,w));