ErrorEllipseTask.cpp

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/*
 * ErrorEllipseTask.cpp
 *
 *  Created on: Feb 11 2022
 *      Author: mkuemmel
 */
 
#include <iostream>
 
#include "SEImplementation/Property/PixelCoordinateList.h"
#include "SEImplementation/Plugin/DetectionFramePixelValues/DetectionFramePixelValues.h"
#include "SEImplementation/Plugin/ErrorEllipse/ErrorEllipse.h"
#include "SEImplementation/Plugin/ShapeParameters/ShapeParameters.h"
#include "SEImplementation/Plugin/PixelCentroid/PixelCentroid.h"
#include "SEImplementation/Plugin/PeakValue/PeakValue.h"
 
#include "SEImplementation/Plugin/ErrorEllipse/ErrorEllipseTask.h"
 
namespace SourceXtractor {
 
void ErrorEllipseTask::computeProperties(SourceInterface& source) const {
  const auto& pixel_variances = source.getProperty<DetectionFramePixelValues>().getVariances();
  const auto& centroid_x = source.getProperty<PixelCentroid>().getCentroidX();
  const auto& centroid_y = source.getProperty<PixelCentroid>().getCentroidY();
  const auto& coordinates = source.getProperty<PixelCoordinateList>().getCoordinateList();
  auto total_intensity = source.getProperty<ShapeParameters>().getIntensity();
  auto singu = source.getProperty<ShapeParameters>().getSinguFlag();
 
  SeFloat x_2_error = 0.0;
  SeFloat y_2_error = 0.0;
  SeFloat x_y_error = 0.0;
 
  SeFloat total_variance = 0;
 
  auto j = pixel_variances.begin();
  for (auto pixel_coord : coordinates) {
        SeFloat variance = *j++;
        SeFloat x_pos = pixel_coord.m_x - centroid_x;
        SeFloat y_pos = pixel_coord.m_y - centroid_y;
 
    x_2_error += x_pos * x_pos * variance;
    y_2_error += y_pos * y_pos * variance;
    x_y_error += x_pos * y_pos * variance;
 
    total_variance  += variance;
  }
 
  SeFloat total_intensity_2 = total_intensity * total_intensity;
  x_2_error /= total_intensity_2;
  y_2_error /= total_intensity_2;
  x_y_error /= total_intensity_2;
 
  //esum *= 0.08333/flux2; // from the original SE2 code
  total_variance *= 0.08333/total_intensity_2;
  // handle fully correlated x/y
  if (singu && (x_2_error*y_2_error-x_y_error*x_y_error)<total_variance*total_variance) {
        x_2_error += total_variance;
        y_2_error += total_variance;
  }
 
  /*------------------------- Error ellipse parameters ------------------------*/
  /*    if (FLAG(obj2.poserr_a))
        {
         double pmx2,pmy2,temp,theta;
 
        if (fabs(temp=obj->poserr_mx2-obj->poserr_my2) > 0.0)
          theta = atan2(2.0 * obj->poserr_mxy,temp) / 2.0;
        else
          theta = PI/4.0;
 
        temp = sqrt(0.25*temp*temp+obj->poserr_mxy*obj->poserr_mxy);
        pmy2 = pmx2 = 0.5*(obj->poserr_mx2+obj->poserr_my2);
        pmx2+=temp;
        pmy2-=temp;
 
        obj2->poserr_a = (float)sqrt(pmx2);
        obj2->poserr_b = (float)sqrt(pmy2);
        obj2->poserr_theta = theta*180.0/PI;
        }
        */
 
  // angle of the error ellipse
  SeFloat theta_error, a_error, b_error;
  SeFloat temp_error = fabs(x_2_error - y_2_error);
  if (temp_error>0.0)
          theta_error = atan2(2.0*x_y_error, temp_error); // when dividing by 2.0 as in SE2 the range is -45 < theta_error < 45 which is smaller than in SE2
  else
          theta_error = M_PI /4.0;
 
  // major/minor axis for the error ellipse
  temp_error = sqrt(0.25*temp_error*temp_error+x_y_error*x_y_error);
  a_error = 0.5*(x_2_error+y_2_error);
  b_error = a_error;
  a_error = sqrt(a_error+temp_error);
  b_error = sqrt(b_error-temp_error);
 
  // set the property
  source.setProperty<ErrorEllipse>(a_error, b_error, theta_error, x_2_error, y_2_error, x_y_error);
}
 
 
}