the present invention relates to spectral image sampling . an image is projected onto an array of optical transformation devices . image intensity values transmitted by said array of optical transformation devices are detected at each sensor element of an image sensor . the image sensor comprises a plurality of photosensitive sensor elements configured to detect a magnitude of incident light , wherein said sensor elements are shaped as regular polygons whose aspect ratio is controlled to minimize sensor element count while obtaining a desired image quality . the detected image intensity values are processed to infer the image .