The scan head with mirrors, lens, filters and CCD is mounted on a transport, which
moves across the target object (area with rice kernels). The transport with scan head is driven
by a stepper motor using a belt gear. The number of physical elements in a CCD array
determines the X-direction sampling rate or optical resolution, and the number of steps per
inch determines the Y-direction sampling rate. The resolution is defined by the quality of
electronics, optics, filters, motor control and the sampling rate. High resolution optics in a 400
dpi scanner is likely to produce better results than a 600 dpi device with poor optics. Most
scanners offer optical resolutions of 600, 1200 or 2,400 dpi. Higher resolutions than the
optical resolution are obtained by interpolation (enhanced resolution). This results not in a
better image quality. FBS can not resolve more than ½ of the optical resolution (Nyquist
sampling theorem). The influence of the scanner resolution on the FBS analysis of rice will be
handled in the Results section