imageTransforms_test.cpp

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/** \file imageTransforms_test.cpp
 */
#include "../../catch2/catch.hpp"
 
#include <vector>
#include <Eigen/Dense>
 
#define MX_NO_ERROR_REPORTS
 
#include "../../../include/math/func/gaussian.hpp"
 
#include "../../../include/improc/imageUtils.hpp"
#include "../../../include/improc/eigenCube.hpp"
 
#include "../../../include/improc/imageTransforms.hpp"
 
#include "../../../include/math/fit/fitGaussian.hpp"
 
/** Scenario: Verify direction and accuracy of various image shifts
 *
 * Tests image shifts by fractional pixels.
 *
 * \anchor tests_improc_imageTransforms_imageShift
 */
SCENARIO( "Verify direction and accuracy of various image shifts", "[improc::imageTransforms]" )
{
    GIVEN( "a Gaussian image" )
    {
        WHEN( "shifting" )
        {
            mx::improc::eigenImage<double> im, shift;
            mx::math::fit::fitGaussian2Dsym<double> fit;
            double x, y;
 
            im.resize( 256, 256 );
            shift.resize( im.rows(), im.cols() );
 
            fit.setArray( shift.data(), shift.rows(), shift.cols() );
 
            // Use sigma = 8 to get a well oversampled image, making shifts more accurate
            mx::math::func::gaussian2D<double>( im.data(), im.rows(), im.cols(), 0., 1.0, 127.5, 127.5, 8 );
            fit.setGuess( 0.0, 1.0, 127.5, 127.5, 8.0 );
 
            mx::improc::imageShift( shift, im, -0.5, -0.5, mx::improc::cubicConvolTransform<double>() );
            fit.fit();
            REQUIRE( fabs( fit.x0() - 127.0 ) < 1e-4 ); // should be much better than this, but this is a test
            REQUIRE( fabs( fit.y0() - 127.0 ) < 1e-4 );
 
            mx::improc::imageShift( shift, im, +0.5, +0.5, mx::improc::cubicConvolTransform<double>() );
            fit.fit();
            REQUIRE( fabs( fit.x0() - 128.0 ) < 1e-4 );
            REQUIRE( fabs( fit.y0() - 128.0 ) < 1e-4 );
 
            mx::improc::imageShift( shift, im, +1.0, +1.0, mx::improc::cubicConvolTransform<double>() );
            fit.fit();
            REQUIRE( fabs( fit.x0() - 128.5 ) < 1e-4 );
            REQUIRE( fabs( fit.y0() - 128.5 ) < 1e-4 );
 
            mx::improc::imageShift( shift, im, +0.5, -0.5, mx::improc::cubicConvolTransform<double>() );
            fit.fit();
            REQUIRE( fabs( fit.x0() - 128.0 ) < 1e-4 );
            REQUIRE( fabs( fit.y0() - 127.0 ) < 1e-4 );
 
            mx::improc::imageShift( shift, im, -0.3, +0.7, mx::improc::cubicConvolTransform<double>() );
            fit.fit();
            REQUIRE( fabs( fit.x0() - 127.2 ) < 1e-3 ); // non-0.5 pixel shifts are harder
            REQUIRE( fabs( fit.y0() - 128.2 ) < 1e-3 );
 
            mx::improc::imageShift( shift, im, 1.3, -0.7, mx::improc::cubicConvolTransform<double>() );
            fit.fit();
            REQUIRE( fabs( fit.x0() - 128.8 ) < 1e-3 );
            REQUIRE( fabs( fit.y0() - 126.8 ) < 1e-3 );
        }
    }
}