In previously known imaging devices as in still and motion cameras, for example, image sensor signal response typically is linear as a function of intensity of incident light. Desirably, however, akin to the response of the human eye, response is sought to be nonlinear and, more particularly, essentially logarithmic. Preferred nonlinearity is realized in image sensor devices of the invention upon severely limiting the number of pixel states, combined with clustering of pixels into what may be termed as super-pixels.