Image2DConvolver.h

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//# Image2DConvolver.h: 2D convolution of an image
//# Copyright (C) 1996,1997,1998,1999,2000,2001,2002,2003
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library 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 Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//#        Internet email: aips2-request@nrao.edu.
//#        Postal address: AIPS++ Project Office
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//# $Id: Image2DConvolver.h 20229 2008-01-29 15:19:06Z gervandiepen $

#ifndef IMAGES_IMAGE2DCONVOLVER_H
#define IMAGES_IMAGE2DCONVOLVER_H

#include <imageanalysis/ImageAnalysis/ImageTask.h>

#include <casa/aips.h>
#include <casa/Arrays/Array.h>
#include <scimath/Mathematics/VectorKernel.h>
#include <casa/Quanta/Quantum.h>

namespace casacore {

template <class T> class ImageInterface;
template <class T> class Matrix;
template <class T> class Vector;
class String;
class IPosition;
class CoordinateSystem;
class ImageInfo;
class Unit;
class GaussianBeam;
}

namespace casa {

// <summary>
// This class does 2D convolution of an image by a functional form
// </summary>

// <use visibility=export>

// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>

// <prerequisite>
//   <li> <linkto class="casacore::ImageInterface">casacore::ImageInterface</linkto>
//   <li> <linkto class="casacore::Convolver">casacore::Convolver</linkto>
// </prerequisite>

// <etymology>
// This class handles 2D convolution of images 
// </etymology>

// <synopsis>
// This class convolves an image by a specified 2D function.
// </synopsis>

// <example>
// <srcBlock>
// </srcBlock>
// </example>

// <motivation>
// Convolution is a standard image processing requirement.  The
// class object has no state.
// The convolution is done via FFT.  Thus input pixels which
// are masked are set to 0 before the convolution.  The mask
// is transferred to the output image.  No additional scaling
// of the output image values is done.
// 
// </motivation>

// <todo asof="2001/08/28">
//   <li> 
// </todo>

template <class T> class Image2DConvolver : public ImageTask<T> {
public:

    const static casacore::String CLASS_NAME;

    Image2DConvolver() = delete;

    Image2DConvolver(
        const SPCIIT image, const casacore::Record *const &regionPtr,
        const casacore::String& mask, const casacore::String& outname,
        const casacore::Bool overwrite
    );
    
    Image2DConvolver(const Image2DConvolver<T> &other) = delete;

    ~Image2DConvolver() {}

    Image2DConvolver &operator=(const Image2DConvolver<T> &other) = delete;

    SPIIT convolve();

    // type is a string that starts with "g" (gaussian), "b" (boxcar), or "h"
    // (hanning), and is case insensitive
    void setKernel(
        const casacore::String& type, const casacore::Quantity& major,
        const casacore::Quantity& minor, const casacore::Quantity& pa
    );

    void setScale(casacore::Double d) { _scale = d; }

    void setAxes(const std::pair<casacore::uInt, casacore::uInt>& axes);

    void setTargetRes(casacore::Bool b) { _targetres = b; }

    casacore::String getClass() const { return CLASS_NAME; }

    // if true, do not log certain info/warning messages which would normally
    // be logged during convolution
    void setSuppressWarnings(casacore::Bool b) { _suppressWarnings = b; }

protected:

       CasacRegionManager::StokesControl _getStokesControl() const {
           return CasacRegionManager::USE_ALL_STOKES;
       }

    std::vector<casacore::Coordinate::Type> _getNecessaryCoordinates() const {
        return std::vector<casacore::Coordinate::Type>();
    }

    inline casacore::Bool _supportsMultipleRegions() const {return true;}

private:
    casacore::VectorKernel::KernelTypes _type;
    casacore::Double _scale;
    casacore::Quantity _major, _minor, _pa;
    casacore::IPosition _axes;
    casacore::Bool _targetres = casacore::False;
    casacore::Bool _suppressWarnings = casacore::False;

    void _checkKernelParameters(
        casacore::VectorKernel::KernelTypes kernelType,
        const casacore::Vector<casacore::Quantity>& parameters
    ) const;

    void _convolve(
        SPIIT imageOut, const casacore::ImageInterface<T>& imageIn,
        casacore::VectorKernel::KernelTypes kernelType
    ) const;

    // returns the value by which pixel values will be scaled
    Double _dealWithRestoringBeam (
        casacore::String& brightnessUnitOut, casacore::GaussianBeam& beamOut,
        const casacore::Array<Double>& kernelArray, Double kernelVolume,
        const casacore::VectorKernel::KernelTypes kernelType,
        const casacore::Vector<casacore::Quantity>& parameters,
        const casacore::CoordinateSystem& cSys,
        const casacore::GaussianBeam& beamIn,
        const casacore::Unit& brightnessUnit, casacore::Bool emitMessage
    ) const;

    void _doMultipleBeams(
        ImageInfo& iiOut, Double& kernelVolume, SPIIT imageOut,
        String& brightnessUnitOut, GaussianBeam& beamOut, Double factor1,
        const ImageInterface<T>& imageIn, const std::vector<Quantity>& originalParms,
        std::vector<Quantity>& kernelParms, Array<Double>& kernel,
        VectorKernel::KernelTypes kernelType, Bool logFactors, Double pixelArea
    ) const;

    // The kernel is currently always real-valued, so make it Double at this
    // point to avoid unnecessary templating issues if the image has is
    // complex valued
    void _doSingleBeam(
        ImageInfo& iiOut, Double& kernelVolume, std::vector<Quantity>& kernelParms,
        Array<Double>& kernel, String& brightnessUnitOut, GaussianBeam& beamOut,
        SPIIT imageOut, const ImageInterface<T>& imageIn,
        const std::vector<Quantity>& originalParms,
        VectorKernel::KernelTypes kernelType, Bool logFactors, Double factor1,
        Double pixelArea
    ) const;

    Double _fillKernel (
        casacore::Matrix<Double>& kernelMatrix,
        casacore::VectorKernel::KernelTypes kernelType,
        const casacore::IPosition& kernelShape,
        const casacore::Vector<casacore::Double>& parameters
    ) const;

    void _fillGaussian(
        Double& maxVal, Double& volume, casacore::Matrix<Double>& pixels,
        Double height, Double xCentre, Double yCentre,
        Double majorAxis, Double ratio, Double positionAngle
    ) const;

    Double _makeKernel(
        casacore::Array<Double>& kernel,
        casacore::VectorKernel::KernelTypes kernelType,
        const std::vector<casacore::Quantity>& parameters,
        const casacore::ImageInterface<T>& inImage
    ) const;

    casacore::IPosition _shapeOfKernel(
        const casacore::VectorKernel::KernelTypes kernelType,
        const casacore::Vector<casacore::Double>& parameters,
        const casacore::uInt ndim
    ) const;

    casacore::uInt _sizeOfGaussian(
        const casacore::Double width, const casacore::Double nSigma
    ) const;

    std::vector<casacore::Quantity> _getConvolvingBeamForTargetResolution(
        const std::vector<casacore::Quantity>& targetBeamParms,
        const casacore::GaussianBeam& inputBeam
    ) const;

    void _logBeamInfo(
        const ImageInfo& imageInfo, const String& desc
    ) const;

    void _log(const String& msg, LogIO::Command priority) const;
};

}

#ifndef CASACORE_NO_AUTO_TEMPLATES
#include <imageanalysis/ImageAnalysis/Image2DConvolver.tcc>
#endif //# CASACORE_NO_AUTO_TEMPLATES
#endif