Rewritable broad-band color filters for spectral image analysis

We propose an optical system to implement rewritable transparent broad-band color filters. The filter consists of a linear variable filter and a liqui d crystal spatial light modulator in which an expected filter function is w ritten. A time-integrated intensity image was taken while the filter was pa ssing the lens aperture of a CCD camera. The averaged norm error between th e implemented and the expected filter functions was about 5.4%. The system was applied to spectral estimation in a two-dimensional color image.