Smoothing Jagged spectra for accurate spectral Sensitivities Recovery

The spectral data acquired in laboratories exhibits sharp peaks, which can be traced to the spectral power distribution of the illumination source. These peaks are especially evident in the first basis functions of the spectral space and hence regularising the spectral sensitivity solution results in jagged sensor curves. In this paper we introduce a method to smooth the spectral data by predicting the sensors response to basis functions under equi-energy illuminant, prior to solv- ing for the spectral sensitivities. We show that estimating the response under equi-energy illumination as a first step in the spectral recovery results in an im- proved sensor estimate.