On geometry of isophote curves in Galilean space

Abstract

In this paper, we introduce isophote curves on surfaces in Galilean 3-space. Apart from the general concept of isophotes, we split our studies into two cases to get the axis d of isophote curves lying on a surface such that d is an isotropic or a non isotropic vector. We also give the method to compute isophote curves of surfaces of revolution. Subsequently, we show the relationship between isophote curves and slant(general) helices on surfaces of revolution obtained by revolving a curve by Euclidean rotations. Finally, we give an example to compute isophote curves on isotropic surfaces of revolution.