Energy balance in Spectral Filter Array camera design

Background: Multispectral imaging permits to capture more spectral information on object surface properties than color imaging. This is useful for machine vision applications. Transmittance spectral filter arrays combined with a solid state sensor form an emerging technology used for snapshot acquisition. In spectral filter arrays technology, the sensitivities of the camera have critical consequences, not only on applications, but also in the viability of the system. We discuss how to balance the energy of each channel in single exposure multispectral imaging. Methods: We propose a methodology to design filters that permits to reach an optimal balance of energy. We apply this method on practical illuminations combined with a Gaussian model of transmittance filters. Results and discussion: Our results demonstrate that we can optimize energetically the global camera response with few efforts for several cases of illumination environments, for a given sensor and a number of spectral channels. This methodology can be embedded in an application-oriented optimization framework. Conclusions: This methodology enables achieving a great range of optical design, and it can be embedded in an application-oriented optimization framework.