Patent ID: 8179457

Claim:
An apparatus, comprising an array of sub-diffraction limit-sized light receptors formed in a substrate having a light receiving surface, each sub-diffraction limit-sized light receptor is configured to output an n-bit element and to change state based on the absorption of at least one photon, where n is an integer greater than 0, where each sub-diffraction limit-sized light receptor is smaller than a 550 nanometer Airy disk diameter; and an optical filter structure disposed over the light receiving surface, the optical filter structure comprised of an array of filter pixels with each filter pixel having an associated passband spectral characteristic, where a data element obtained from said array of sub-diffraction limit-sized light receptors is comprised of a combination of a plurality of said n-bit elements output from a plurality of sub-diffraction limit-sized light receptors that underlie filter pixels having at least two different passband spectral characteristics, where the filter pixels having at least two different passband spectral characteristics comprise a gradient filter wherein bandpass regions increase when moving from a central region of the gradient filter towards an edge region of the gradient filter.