Fig. 3From: Intensity-curvature functional based digital high pass filter of the bivariate cubic B-spline model polynomial function(a), (a1), (a2) Original images. Here, (a) is calculated using spherical light source, (a1) is the calculated light torus, and (a2) is the calculated elliptical light. (b), (b1), (b2) ICF of the bivariate cubic B-spline model function (eq. (11)). (c), (c1), (c2) TF of ICF-based HPF (eq. (12)). (d), (d1), (d2) k-space magnitude of ICFBack to article page