Optimal spectral sensitivity functions for single sensor color imaging

Citation:

Z. Sadeghipoor, Y. M. Lu, and S. Süsstrunk, “Optimal spectral sensitivity functions for single sensor color imaging,” in Proc. SPIE Conference on Digital Photography VIII, Burlingame, 2012.

Date Presented:

Jan.

Abstract:

A cost-effective and convenient approach for color imaging is to use a single sensor and mount a color filter array
(CFA) in front of it, such that at each spatial position the scene information in one color channel is captured. To
estimate the missing colors at each pixel, a demosaicing algorithm is applied to the CFA samples. Besides the
filter arrangement and the demosaicing method, the spectral sensitivity functions of the CFA filters considerably
affect the quality of the demosaiced image. In this paper, we extend the algorithm presented by Lu and Vetterli,
originally proposed for designing the optimum CFA, to compute the optimum spectral sensitivities. The proposed
algorithm solves a constrained optimization problem to find optimum spectral sensitivities and the corresponding
linear demosaicing method. An important constraint for this problem is the smoothness of spectral sensitivities,
which is imposed by modeling these functions as a linear combination of several smooth kernels. Simulation
results verify the effectiveness of the proposed algorithm in finding optimal spectral sensitivity functions, which
outperform measured camera sensitivity functions.