In this letter, we present an optoelectronic system for fast gray-level ima
ge decomposition into binary slices. To perform thresholding, we are making
use of the differential nature of optical thyristors and compare the light
level of the image pixels to that of a reference intensity. As input a gra
y-level image was generated using a nematic liquid crystal spatial light mo
dulator (SLM) and as a reference intensity a VCSEL light source combined wi
th a diffractive fan-out element was used, We also introduced a compact, la
rge field of view telecentric optical system based on gradient refractive i
ndex lenses to image between the SLM and the array. A frame rate decomposit
ion of a six gray-level image has been obtained at 1.8 kHz. Future prospect
s for system improvements are discussed.