Image sensor equipped with additional group of selectively transmissive filters for illuminant estimation, and associated illuminant estimation method

摘要

An image sensor includes a two dimensional array of pixel elements, a color filter array, and a digital circuit. The color filter array is superimposed on and in registration with the two dimensional array of pixel elements. The color filter array includes a first group of selectively transmissive filters and a second group of selectively transmissive filters. The first group of selectively transmissive filters is arranged to selectively transmit spectral energy in M colors of the visible spectrum, wherein M is larger than two. The second group of selectively transmissive filters is arranged to selectively transmit spectral energy in N colors of the visible spectrum, wherein any selectively transmissive filter of the first and the second groups of selectively transmissive filters is arranged to transmit spectral energy in one specific color of the visible spectrum, and N is larger than M. An associated illuminant estimation method is also provided.