A computer receives asynchronous information originating from a light sensor (10) having a pixel matrix disposed opposite a scene. The asynchronous information comprises, for each pixel of the matrix, successive events originating from this pixel and depending on variations in light in the scene. For a place of estimation (p) in the matrix of pixels and an estimation time (t), the computer selects a set (Sp t) of events originating from pixels included in a spatial neighborhood (πρ) of the place of estimation and which have occurred in a time interval (Θ) defined with respect to the estimation time, such that this set has at most one event per pixel of the spatial neighborhood. The computer quantifies the variations in the times of occurrence of the events of the set selected as a function of the positions, in the matrix, of the pixels from which these events originate.