A sensor array includes includes multiple sensor elements that each have a collection electrode in contact with a photosensitive layer. The photosensitive layer is configured to produce a detectable response at the collection electrode upon incidence of radiation in a responsive zone of the photosensitive layer. A gate electrode layer is separated from the photosensitive layer by a dielectric layer, with adjustments to voltage applied to the gate electrode layer inducing changes in areal extent of the responsive zone of the photosensitive layer. Changing the size of the responsive zone permits performance of image convolutions for edge detection, data compression, or other Gaussian convolutions by the sensor array, rather than by post-detection electronics.