In this paper an optoelectronic system for fast grey-level image decomposit
ion into binary slices is presented. To perform thresholding we take advant
age of the differential nature of optical thyristors and compare the light
level of the image pixels with that of a reference intensity. For the input
a grey-level image was generated using a liquid crystal spatial light modu
lator (SLM) and, for the reference intensity, a vertical-cavity surface-emi
tting laser light source combined with a diffractive fan-out element was us
ed. A decomposition frame rate of 1.0 kHz has been obtained for images with
five grey levels.