Development of the computer vision system for
shaking analysis
The samples were shaken by means of a laboratory unidirectional
shaker device (Fig. 1) with a continuously adjustable
rotational speed between 0 and 20 Hz and 4 possible strokes:
60, 100, 140 and 180 mm. The stems of the fruit were attached
to the shaker by a drill chuck.
A high-speed digital colour video camera CASIO model EXF1
was used to record the movement of different fruits at a
rate of 300 fps. Each image had a size of 512 384 pixels. The
fruit was placed in front of a black background under natural
lighting. Different video sequences were acquired at different
times of the day using a diffuse reflecting surface to make the
light more uniform and to minimise the variability of the
natural light. Figure 1 shows the set-up used in the experiments.
The fruit used to develop and tune the image-processing
algorithms were ‘Valencia’ oranges, ‘Nova’ mandarins
and ‘Eureka’ lemons. This fruit was different from those used
in the experiments to study the movement of the fruit.