System for determining the two-dimensional characteristic function of a continuous optical transformation element

摘要

P A source (20) projects through a pattern (MI) an incident light beam (FI) on a surface (S) of a continuous image conversion element (22). The target defines transparent and opaque surfaces (S1, S2) delimited by an angle. An optoelectronic device (23) converts elementary brightness levels (IR (ui, vj)) of an image (IR) produced by the element (22) in response to the incident beam, respectively into electrical levels (IRu i, vj). A calculator (25) calculates a two-dimensional partial derivative for the electrical level corresponding to each of the elementary brightness levels of the resulting image as a function of electrical levels in response to elementary levels of brightness contiguous to each of the elementary levels to produce the function characteristic. / P