A measurement-based spectral generator for colors

This paper proposes a new approach to constructing spectra for colors based on measured spectra. Reflectances of a set of 1,400 color samples are measured using a spectroradiometer. Given any color, its spectrum is generated in terms of a tightly enclosing tetrahedron formed by measured color points. A method is also proposed to enlarge the span region of the base spectra for spectral generation. Using our approach, the derived spectra correspond closely to the reality and the deriving operation works almost for any color.