title: Multispectral color image capture using a liquid crystal tunable filter
abstract: We describe the experimental setup of a multispectral color image acquisition system consisting of a professional monochrome CCD camera and a tunable filter in which the spectral transmittance can be controlled electronically. We perform a spectral characterization of the acquisition system taking into account the acquisition noise. To convert the camera output signals to device-independent color data, two main approaches are proposed and evaluated. One consists in applying regression methods to convert from the K camera outputs to a device-independent color space such as CIEXYZ or CIELAB. Another method is based on a spectral model of the acquisition system. By inverting the model using a principal eigenvector approach, we estimate the spectral reflectance of each pixel of the imaged surface
keyphrases: multispectral color image capture liquid crystal tunable filter tunable filter multispectral color image acquisition system acquisition system monochrome CCD camera spectral transmittance spectral characterization acquisition noise camera output signals camera outputs device-independent color data regression methods CIEXYZ CIELAB spectral model principal eigenvector approach spectral reflectance pixel imaged surface independent color space