A simple optoelectronic architecture for carrying out optical thresholding operations is proposed. The architecture is suitable for optical neural network implementations and for image processing. The module is based on liquid-crystal television, on a CCD camera, and on beam-sampling optical components. The module does not need an additional light source, shows translation invariance, and does not break the beam propagation path. Experimental results involving images and correlations are presented. Finally, an architecture for an automatic winner-take-all extractor for neural network architectures is proposed.