Chris@166: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@166: 
Chris@166: #include "maths/MedianFilter.h"
Chris@166: 
Chris@166: #include <cmath>
Chris@182: #include <cstdlib>
Chris@166: 
Chris@166: #define BOOST_TEST_DYN_LINK
Chris@166: #define BOOST_TEST_MAIN
Chris@166: 
Chris@166: #include <boost/test/unit_test.hpp>
Chris@166: 
Chris@166: BOOST_AUTO_TEST_SUITE(TestMedianFilter)
Chris@166: 
Chris@166: BOOST_AUTO_TEST_CASE(odd)
Chris@166: {
Chris@166:     // A median filter of size N always retains a pool of N elements,
Chris@166:     // which start out all-zero. So the output median will remain zero
Chris@166:     // until N/2 elements have been pushed.
Chris@166:     MedianFilter<double> f(3);
Chris@166:     f.push(1);			// 0 0 1
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     f.push(-3);			// 0 1 -3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     f.push(5);			// 1 -3 5
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 1);
Chris@166:     f.push(7);			// -3 5 7
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     f.push(3);			// 5 7 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     f.push(3);			// 7 3 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 3);
Chris@166: }
Chris@166: 
Chris@166: BOOST_AUTO_TEST_CASE(even)
Chris@166: {
Chris@166:     // Our median does not halve the difference (should it??), it just
Chris@166:     // returns the next element from the input set
Chris@166:     MedianFilter<double> f(4);
Chris@166:     f.push(1);			// 0 0 0 1
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     f.push(-3);			// 0 0 1 -3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     f.push(5);			// 0 1 -3 5
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 1);
Chris@166:     f.push(7);			// 1 -3 5 7
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     f.push(3);			// -3 5 7 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     f.push(3);			// 5 7 3 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166: }
Chris@166: 
Chris@166: BOOST_AUTO_TEST_CASE(odd75)
Chris@166: {
Chris@166:     MedianFilter<double> f(5, 75.f);
Chris@166:     f.push(1);			// 0 0 0 0 1
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     f.push(-3);			// 0 0 0 1 -3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 0);
Chris@166:     f.push(5);			// 0 0 1 -3 5
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 1);
Chris@166:     f.push(7);			// 0 1 -3 5 7
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     f.push(3);			// 0 -3 5 7 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     f.push(3);			// 0 5 7 3 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166: }
Chris@166: 
Chris@166: BOOST_AUTO_TEST_CASE(even75)
Chris@166: {
Chris@166:     MedianFilter<double> f(4, 75.f);
Chris@166:     f.push(1);			// 0 0 0 1
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 1);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 1);
Chris@166:     f.push(-3);			// 0 0 1 -3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 1);
Chris@166:     f.push(5);			// 0 1 -3 5
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 5);
Chris@166:     f.push(7);			// 1 -3 5 7
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 7);
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 7);
Chris@166:     f.push(3);			// -3 5 7 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 7);
Chris@166:     f.push(3);			// 5 7 3 3
Chris@166:     BOOST_CHECK_EQUAL(f.get(), 7);
Chris@166: }
Chris@166: 
Chris@167: BOOST_AUTO_TEST_CASE(oddStandalone)
Chris@167: {
Chris@167:     // The standalone (static filter() method) function is intended to
Chris@167:     // match e.g. MATLAB median filter, filtering a row at once
Chris@167:     // assuming the values beyond its edges are zeroes. This basically
Chris@167:     // just means it needs to compensate for the latency in the raw
Chris@167:     // filter:
Chris@167:     //
Chris@167:     // Raw filter
Chris@167:     //    1 3 5 7   ->   0 1 3 5    (N=3)
Chris@167:     // (because at each step only the values up to that step are
Chris@167:     // available)
Chris@167:     //
Chris@167:     // Standalone function:
Chris@167:     //    1 3 5 7   ->   1 3 5 5    (N=3)
Chris@167:     
Chris@167:     std::vector<double> in;
Chris@167:     in.push_back(1);
Chris@167:     in.push_back(3);
Chris@167:     in.push_back(5);
Chris@167:     in.push_back(7);
Chris@167: 
Chris@167:     std::vector<double> out = MedianFilter<double>::filter(3, in);
Chris@167:     BOOST_CHECK_EQUAL(out[0], 1);
Chris@167:     BOOST_CHECK_EQUAL(out[1], 3);
Chris@167:     BOOST_CHECK_EQUAL(out[2], 5);
Chris@167:     BOOST_CHECK_EQUAL(out[3], 5);
Chris@167: }
Chris@167: 
Chris@167: BOOST_AUTO_TEST_CASE(evenStandalone)
Chris@167: {
Chris@167:     // See above. But note that the even length does not match the
Chris@167:     // MATLAB because it doesn't halve the middle, as MATLAB does
Chris@167: 
Chris@167:     std::vector<double> in;
Chris@167:     in.push_back(1);
Chris@167:     in.push_back(3);
Chris@167:     in.push_back(5);
Chris@167:     in.push_back(7);
Chris@167: 
Chris@167:     std::vector<double> out = MedianFilter<double>::filter(4, in);
Chris@167:     BOOST_CHECK_EQUAL(out[0], 3);
Chris@167:     BOOST_CHECK_EQUAL(out[1], 5);
Chris@167:     BOOST_CHECK_EQUAL(out[2], 5);
Chris@167:     BOOST_CHECK_EQUAL(out[3], 5);
Chris@167: }
Chris@167: 
Chris@167: BOOST_AUTO_TEST_CASE(standaloneEmpty)
Chris@167: {
Chris@167:     std::vector<double> in;
Chris@167:     std::vector<double> out1 = MedianFilter<double>::filter(3, in);
Chris@167:     BOOST_CHECK_EQUAL(out1.size(), 0);
Chris@167:     std::vector<double> out2 = MedianFilter<double>::filter(4, in);
Chris@167:     BOOST_CHECK_EQUAL(out2.size(), 0);
Chris@167: }
Chris@167: 
Chris@167: BOOST_AUTO_TEST_CASE(types)
Chris@167: {
Chris@167:     MedianFilter<double> dfilt(3);
Chris@167:     dfilt.push(1.2);
Chris@167:     BOOST_CHECK_EQUAL(dfilt.get(), 0.0);
Chris@167:     dfilt.push(2.4);
Chris@167:     BOOST_CHECK_EQUAL(dfilt.get(), 1.2);
Chris@167:     dfilt.push(1e-6);
Chris@167:     BOOST_CHECK_EQUAL(dfilt.get(), 1.2);
Chris@167:     dfilt.push(1e6);
Chris@167:     BOOST_CHECK_EQUAL(dfilt.get(), 2.4);
Chris@167: 
Chris@167:     MedianFilter<int> ifilt(3);
Chris@167:     ifilt.push(1);
Chris@167:     BOOST_CHECK_EQUAL(ifilt.get(), 0);
Chris@167:     ifilt.push(2);
Chris@167:     BOOST_CHECK_EQUAL(ifilt.get(), 1);
Chris@167:     ifilt.push(0);
Chris@167:     BOOST_CHECK_EQUAL(ifilt.get(), 1);
Chris@167:     ifilt.push(1000);
Chris@167:     BOOST_CHECK_EQUAL(ifilt.get(), 2);
Chris@167: }
Chris@167: 
Chris@182: BOOST_AUTO_TEST_CASE(inf)
Chris@182: {
Chris@182:     // Inf and -Inf should behave normally
Chris@182:     double pinf = strtod("Inf", 0);
Chris@182:     double ninf = strtod("-Inf", 0);
Chris@182:     MedianFilter<double> dfilt(3);
Chris@182:     dfilt.push(1.0);
Chris@182:     dfilt.push(2.0);
Chris@182:     dfilt.push(pinf);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), 2.0);
Chris@182:     dfilt.push(pinf);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), pinf);
Chris@182:     dfilt.push(pinf);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), pinf);
Chris@182:     dfilt.push(2.0);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), pinf);
Chris@182:     dfilt.push(1.0);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), 2.0);
Chris@182:     dfilt.push(ninf);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), 1.0);
Chris@182:     dfilt.push(pinf);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), 1.0);
Chris@182:     dfilt.push(ninf);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), ninf);
Chris@182: }
Chris@182: 
Chris@182: BOOST_AUTO_TEST_CASE(nan)
Chris@182: {
Chris@182:     // The filter should never accept a NaN, because it breaks sorting
Chris@182:     // and comparison and that will break the filter. Instead it
Chris@182:     // should insert 0.
Chris@182:     double nan = strtod("NaN", 0);
Chris@182:     MedianFilter<double> dfilt(3);
Chris@182:     dfilt.push(1.0);
Chris@182:     dfilt.push(2.0);
Chris@182:     dfilt.push(nan);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), 1.0);
Chris@182:     dfilt.push(nan);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), 0.0);
Chris@182:     dfilt.push(-11.0);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), 0.0);
Chris@182:     dfilt.push(-1.0);
Chris@182:     BOOST_CHECK_EQUAL(dfilt.get(), -1.0);
Chris@182: }
Chris@182: 
Chris@166: BOOST_AUTO_TEST_SUITE_END()
Chris@166: 
Chris@166: