“…In this article, we provide prerequisites for solving numerically the inverse problem to be specified in the following. Inspired by Kaltenbacher and Lorenzi and following the authors of , we suppose to have a dictionary { C 1 , C 2 ,…, C N } consisting of functions C K = C K ( x , Y ), K = 1,…, N , given such that with positive constants α K >0, K = 1,…, N . In that way, the searched function C is projected onto a dictionary consisting of physically meaningful elements such as polyconvex functions .…”