Threshold.cc

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/*
 * LSST Data Management System
 * Copyright 2008, 2009, 2010 LSST Corporation.
 *
 * This product includes software developed by the
 * LSST Project (http://www.lsst.org/).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the LSST License Statement and
 * the GNU General Public License along with this program.  If not,
 * see <http://www.lsstcorp.org/LegalNotices/>.
 */
#include <cstdint>
#include <cmath>
#include <string>
#include <boost/format.hpp>
#include "lsst/pex/exceptions.h"
#include "lsst/log/Log.h"
#include "lsst/afw/math/Statistics.h"
#include "lsst/afw/image/Image.h"
#include "lsst/afw/image/MaskedImage.h"
#include "lsst/afw/detection/Threshold.h"

namespace lsst {
namespace afw {
namespace detection {

Threshold::ThresholdType Threshold::parseTypeString(std::string const& typeStr) {
    if (typeStr.compare("bitmask") == 0) {
        return Threshold::BITMASK;
    } else if (typeStr.compare("value") == 0) {
        return Threshold::VALUE;
    } else if (typeStr.compare("stdev") == 0) {
        return Threshold::STDEV;
    } else if (typeStr.compare("variance") == 0) {
        return Threshold::VARIANCE;
    } else if (typeStr.compare("pixel_stdev") == 0) {
        return Threshold::PIXEL_STDEV;
    } else {
        throw LSST_EXCEPT(lsst::pex::exceptions::InvalidParameterError,
                          (boost::format("Unsupported Threshold type: %s") % typeStr).str());
    }
}

std::string Threshold::getTypeString(ThresholdType const& type) {
    if (type == VALUE) {
        return "value";
    } else if (type == STDEV) {
        return "stdev";
    } else if (type == VARIANCE) {
        return "variance";
    } else {
        throw LSST_EXCEPT(lsst::pex::exceptions::InvalidParameterError,
                          (boost::format("Unsopported Threshold type: %d") % type).str());
    }
}

double Threshold::getValue(const double param) const {
    switch (_type) {
        case STDEV:
            if (param <= 0) {
                throw LSST_EXCEPT(lsst::pex::exceptions::InvalidParameterError,
                                  (boost::format("St. dev. must be > 0: %g") % param).str());
            }
            return _value * param;
        case VALUE:
        case BITMASK:
        case PIXEL_STDEV:
            return _value;
        case VARIANCE:
            if (param <= 0) {
                throw LSST_EXCEPT(lsst::pex::exceptions::InvalidParameterError,
                                  (boost::format("Variance must be > 0: %g") % param).str());
            }
            return _value * std::sqrt(param);
        default:
            throw LSST_EXCEPT(lsst::pex::exceptions::InvalidParameterError,
                              (boost::format("Unsupported type: %d") % _type).str());
    }
}

template <typename ImageT>
double Threshold::getValue(ImageT const& image) const {
    double param = -1;  // Parameter for getValue()
    if (_type == STDEV || _type == VARIANCE) {
        math::Statistics stats = math::makeStatistics(image, math::STDEVCLIP);
        double const sd = stats.getValue(math::STDEVCLIP);

        LOGL_DEBUG("afw.detection.threshold", "St. Dev = %g", sd);

        if (_type == VARIANCE) {
            param = sd * sd;
        } else {
            param = sd;
        }
    }
    return getValue(param);
}

Threshold createThreshold(double const value, std::string const typeStr, bool const polarity) {
    return Threshold(value, Threshold::parseTypeString(typeStr), polarity);
}

//
// Explicit instantiations
//
#define INSTANTIATE(TYPE)                                                          \
    template double Threshold::getValue(image::TYPE<unsigned short> const&) const; \
    template double Threshold::getValue(image::TYPE<int> const&) const;            \
    template double Threshold::getValue(image::TYPE<float> const&) const;          \
    template double Threshold::getValue(image::TYPE<double> const&) const;         \
    template double Threshold::getValue(image::TYPE<std::uint64_t> const&) const;

#ifndef DOXYGEN
INSTANTIATE(Image);
INSTANTIATE(MaskedImage);
#endif
}  // namespace detection
}  // namespace afw
}  // namespace lsst