Image2DConvolver.h

Go to the documentation of this file.

//# 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
//#                        National Radio Astronomy Observatory
//#                        520 Edgemont Road
//#                        Charlottesville, VA 22903-2475 USA
//#
//# $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/Logging/LogIO.h>
#include <casa/Arrays/Array.h>
#include <scimath/Mathematics/VectorKernel.h>
#include <casa/Quanta/Quantum.h>

namespace casa {

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;

// <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="ImageInterface">ImageInterface</linkto>
//   <li> <linkto class="Convolver">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 String CLASS_NAME;

        Image2DConvolver() = delete;

        Image2DConvolver(
                const SPCIIT image, const Record *const &regionPtr,
            const String& mask, const String& outname, const 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 String& type, const Quantity& major, const Quantity& minor,
                const Quantity& pa
        );

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

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

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

        String getClass() const { return CLASS_NAME; }

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

protected:

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

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

    inline Bool _supportsMultipleRegions() const {return True;}

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

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

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

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

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

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

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

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

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

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

}

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