“…A first group uses elementary descriptors, such as the circularity and elliptical factors, which do not offer the best results due to their simplicity (Wheeless et al, 1994;Fernández et al, 2013). Some other recent approaches propose ellipse fitting (Gonzalez-Hidalgo et al, 2015), Hough transform (Mazalan et al, 2013), circlet transform (Sarrafzadeh et al, 2015), the computation of descriptors using Fourier series (Frejlichowski, 2010;Aziz , 2013), classification via artificial neural networks (Durant et al, 2017;Rahmat et al, 2018;Dalvi and Vernekar , 2016), the analysis of curvature changes (Delgado et al, 2016) and the use of integral geometry-based functions to obtain efficient descriptors of the erythrocyte contour (Gual et al, 2013;2015a). All these approaches make it possible to compare and analyze the shape of erythrocytes in the feature space, but they are not suitable for computing shape statistics, such as mean shapes, or capturing the principal directions of shape variation within a specific class or between the cells in a normal and/or deformed cell class.…”