The problem of surface reconstruction from slope or curvature measurem
ents of rectangular areas has been examined by use of the orthogonalit
y property of Legendre polynomials. A relation is given between the in
tegrals involving slope or curvature data and the coefficients used in
the expansion of the surface with such polynomials. Tt is shown that
those coefficients are retrieved independently of each other. The effi
ciency and stability of the method have been tested with numerical exa
mples. (C) 1997 Optical Society of America.