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#ifndef PRIMARY_BEAM_IMAGE_SET
#define PRIMARY_BEAM_IMAGE_SET
#include <array>
#include <boost/filesystem/operations.hpp>
#include <aocommon/hmatrix4x4.h>
#include <aocommon/image.h>
#include <aocommon/matrix2x2.h>
#include <aocommon/polarization.h>
#include <aocommon/fits/fitsreader.h>
#include <radler/component_list.h>
namespace wsclean {
/**
* A set of images that describe the beam correction. The image set
* has maximally 16 images that present the 16 elements of a Hermitian Mueller
* matrix. In the case not all elements are required (e.g. for Stokes I
* correction), some of the images may remain empty (i.e. unallocated),
* indicating these elements should be assumed to be zero.
*
* All images should have the same size at all time, unless they are empty.
*/
class PrimaryBeamImageSet {
public:
PrimaryBeamImageSet() {}
PrimaryBeamImageSet(size_t width, size_t height) {
for (size_t i = 0; i != _beamImages.size(); ++i)
_beamImages[i] = aocommon::Image(width, height);
}
void SetToZero() {
for (aocommon::Image& img : _beamImages) img = 0.0f;
}
double GetUnpolarizedCorrectionFactor(size_t x, size_t y) const {
const double stokes_i = StokesIValue(x + y * Width());
return stokes_i != 0.0 ? (1.0 / stokes_i) : 0.0;
}
const aocommon::Image& operator[](size_t index) const {
return _beamImages[index];
}
aocommon::Image& operator[](size_t index) { return _beamImages[index]; }
PrimaryBeamImageSet& operator+=(const PrimaryBeamImageSet& rhs) {
if (_beamImages.size() != rhs._beamImages.size())
throw std::runtime_error("Primary beam image sets don't match");
for (size_t i = 0; i != _beamImages.size(); ++i) {
if (_beamImages[i].Empty())
_beamImages[i] = rhs._beamImages[i];
else if (!rhs._beamImages[i].Empty())
_beamImages[i] += rhs._beamImages[i];
}
return *this;
}
PrimaryBeamImageSet& operator*=(double factor) {
for (aocommon::Image& image : _beamImages) image *= factor;
return *this;
}
void ApplyStokesI(float* stokes_i, double beam_limit) const {
assert(beam_limit >= 0);
const size_t size = _beamImages[0].Size();
for (size_t j = 0; j != size; ++j) {
const double beam_value = StokesIValue(j);
if (beam_value <= beam_limit) {
stokes_i[j] = std::numeric_limits<float>::quiet_NaN();
} else {
const double inverted_beam = 1.0 / beam_value;
stokes_i[j] *= inverted_beam;
}
}
}
void ApplyDiagonal(float* images[2], double beamLimit) const {
// The beam will be compared to a squared quantity (matrix norm), so square
// it:
beamLimit = beamLimit * beamLimit;
const size_t size = _beamImages[0].Size();
for (size_t j = 0; j != size; ++j) {
// xx' = xx * m_00 + yy * m_03
// yy' = xx * m_30 + yy * m_33
// Simplify the Mueller matrix to a 2x2 matrix so it can be
// properly inverted.
aocommon::MC2x2 beam = Value2x2(j);
if (Norm(beam) > beamLimit && beam.Invert()) {
const double xx = images[0][j];
const double yy = images[1][j];
images[0][j] = xx * beam.Get(0).real() + yy * beam.Get(1).real();
images[1][j] = xx * beam.Get(2).real() + yy * beam.Get(3).real();
} else {
for (size_t p = 0; p != 2; ++p)
images[p][j] = std::numeric_limits<float>::quiet_NaN();
}
}
};
void ApplyFullStokes(float* images[4], double beamLimit) const {
// The beam will be compared to a squared quantity (matrix norm), so square
// it:
beamLimit = beamLimit * beamLimit;
const size_t size = _beamImages[0].Size();
for (size_t j = 0; j != size; ++j) {
aocommon::HMC4x4 beam = Value(j);
if (beam.Norm() > beamLimit) {
if (!beam.Invert()) beam = aocommon::HMC4x4::Zero();
double stokesVal[4] = {images[0][j], images[1][j], images[2][j],
images[3][j]};
aocommon::Vector4 v;
aocommon::Polarization::StokesToLinear(stokesVal, v.data());
v = beam * v;
aocommon::Polarization::LinearToStokes(v.data(), stokesVal);
for (size_t p = 0; p != 4; ++p) images[p][j] = stokesVal[p];
} else {
for (size_t p = 0; p != 4; ++p)
images[p][j] = std::numeric_limits<float>::quiet_NaN();
}
}
}
/**
* @brief Correct component list for primary beam given a (output)
* channel index.
*/
void CorrectComponentList(radler::ComponentList& componentList,
size_t channel) {
componentList.MergeDuplicates();
for (size_t i = 0; i != componentList.NScales(); ++i) {
const aocommon::UVector<radler::ComponentList::Position>& positions =
componentList.GetPositions(i);
for (size_t j = 0; j != positions.size(); ++j) {
const double beamCorrectionFactor =
GetUnpolarizedCorrectionFactor(positions[j].x, positions[j].y);
componentList.MultiplyScaleComponent(i, j, channel,
beamCorrectionFactor);
}
}
}
static constexpr size_t NImages() { return kNImages; }
size_t Width() const { return _beamImages[0].Width(); }
size_t Height() const { return _beamImages[0].Height(); }
private:
aocommon::HMC4x4 Value(size_t x, size_t y) const {
return Value(x + y * Width());
}
aocommon::HMC4x4 Value(size_t pixel_index) const {
aocommon::HMC4x4 beam_values;
for (size_t i = 0; i != kNImages; ++i) {
if (!_beamImages[i].Empty()) {
beam_values.Data(i) = _beamImages[i][pixel_index];
}
}
return beam_values;
}
/**
* Returns a 2x2 matrix for diagonal correction.
*/
aocommon::MC2x2 Value2x2(size_t pixel_index) const {
const double xx_to_xx = _beamImages[0][pixel_index]; // m_00
const double yy_to_yy = _beamImages[15][pixel_index]; // m_33
const double xx_to_yy_r =
_beamImages[9].Empty() ? 0.0 : _beamImages[9][pixel_index];
const double xx_to_yy_i =
_beamImages[10].Empty() ? 0.0 : _beamImages[10][pixel_index];
return aocommon::MC2x2{xx_to_xx,
{xx_to_yy_r, -xx_to_yy_i},
{xx_to_yy_r, xx_to_yy_i},
yy_to_yy};
}
double StokesIValue(size_t pixel_index) const {
const double xx_to_xx = _beamImages[0][pixel_index]; // m_00
const double yy_to_yy = _beamImages[15][pixel_index]; // m_33
const double xx_to_yy = _beamImages[9].Empty()
? 0.0
: _beamImages[9][pixel_index]; // real(m_30)
// (xx_to_xx + yy_to_yy + m_30 + m_03) / 2
// = 0.5 * (xx_to_xx + yy_to_yy + m_30 + conj(m_30))
// = 0.5 * (xx_to_xx + yy_to_yy) + real(m_30)
return 0.5 * (xx_to_xx + yy_to_yy) + xx_to_yy;
}
static constexpr size_t kNImages = 16;
/**
* Some images of this array may be left unset if they are not relevant for
* the beam correction (e.g. for Stokes I correction). The first and last
* images are always set, unless the entire PrimaryBeamImageSet object is
* empty.
*/
std::array<aocommon::Image, kNImages> _beamImages;
};
} // namespace wsclean
#endif
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