A silicon retina calculating high-precision spatial and temporal derivatives

A silicon retina was fabricated to emulate two fundamental types of response in the vertebrate retinal circuit, i.e. the sustained response and the transient response. The outputs of the silicon retina emulating the sustained response exhibit a Laplacian-Gaussian-like receptive field and therefore carry out a smoothing and contrast enhancement on input images. The outputs emulating the transient response were obtained by subtracting subsequent images that were smoothed by a resistive network and therefore are sensitive to moving object. The chip was applied for a real time image processing in indoor illumination