Figure 1.

(A) The parameters defining the face space. The red points indicate the landmarks, α = 1, …, 18, whose 2D varying Cartesian coordinates generate the continuum of face space. The face space points are parametrised in terms of vectors f whose components are the Cartesian coordinates of a set of non-redundant landmarks ${\overrightarrow{\ell }}_{\alpha }$ (signaled with an empty circle), or in terms of (vertical or horizontal) distances d_i (i = 0, …, 10) among some pairs of landmarks $d_i=|x_{\alpha (i)}-x_{\beta (i)}|$ or $d_i=|y_{\alpha (i)}-y_{\beta (i)}|$ (arrows). (B) Reference portrait RP1 used in experiment E1 along with its corresponding landmarks (in blue). (C) Image deformation of RP1 according to a given vector of inter-landmark distances d: the blue reference portrait landmarks are shifted (leading to the red points) so that their inter-landmark distances are d, and the reference image (B) is consequently deformed. (D) Image deformation of the reference portrait RP2 according to the same vector of distances d as in (C).