Colour Converter - Reflectance spectra to CIE1964 space

Code to calculate coordinates within the colour space CIE 1964 with 10° Supplementary Standard Observer under six CIE Illuminants

The code allows to convert reflectance into coordinates within the color space CIE 1964 (10° Supplementary Standard Observer) at 5-nm measurement sampling, under six CIE Illuminants: A, C and four illuminants of the D (Daylight) series: D50, D55, D65, D75. The function performs automatically spectral thresholding to the 380-780 nm range of wavelengths and performs extrapolation of the missing data within the range of calculation through 1-D linear algorithms.
The output is expressed as L*, a*, b* and considers objects illuminated under a D65 illuminant ranging in the visible gamut L* = [0, 100], a* and b* = [-127, 127].