X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=85e07e09b273bffd4bfa58903e7d108771450eb1;hb=17f20398d8bb0e4b97b5884b999bbe8d58c5254f;hp=26c1c0eda20c5ddd42a29d450817732c2f5d80d1;hpb=1f05afcd917bbf8b56a9446e4f937864f09b33f4;p=ctsim.git diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp index 26c1c0e..85e07e0 100644 --- a/libctsim/filter.cpp +++ b/libctsim/filter.cpp @@ -7,9 +7,9 @@ ** Date Started: Aug 1984 ** ** This is part of the CTSim program -** Copyright (C) 1983-2000 Kevin Rosenberg +** Copyright (c) 1983-2000 Kevin Rosenberg ** -** $Id: filter.cpp,v 1.34 2001/01/12 03:49:07 kevin Exp $ +** $Id: filter.cpp,v 1.37 2001/02/16 00:28:41 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 @@ -30,26 +30,32 @@ 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 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* SignalFilter::s_aszFilterName[] = { {"abs_bandlimit"}, {"abs_hamming"}, + {"abs_hanning"}, {"abs_cosine"}, - {"abs_sinc"}, {"shepp"}, + {"abs_sinc"}, {"bandlimit"}, {"sinc"}, {"hamming"}, + {"hanning"}, {"cosine"}, {"triangle"}, }; @@ -57,12 +63,14 @@ const char* SignalFilter::s_aszFilterName[] = { const char* 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"}, }; @@ -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));