The colour of the conveyor belts was chosen to enhance the contrast between the belts and arils in order to make segmentation of the images easier. Conveyor belts of different colours were tested before being installed on the prototype. These preliminary tests consisted in acquiring and segmenting images of arils and internal membranes placed over pieces of white, blue, dark green,light green and grey belts and then measuring the ratio of successfulclassification (Blasco et al., 2008).