The spectral camera system used in this research is shown in Fig. 1. The light source, lens, spectrograph device and monochrome CCD camera are mounted on an X-Y scan bed. Each scan line includes 1600 pixels and each pixel consists of 800 samplings from different wavelengths in the visible bandwidth, which are consequently interpolated into 36 samplings from 380nm to 730nm in 10 nm increments. Each wavelength reading is recorded in 16-bit encoding by the monochrome CCD camera. A Xenon light source is guided by two optical fibres to provide the illumination in two overlapping vertical lines from each