Determination of defects. The main defects suffered by
sweet tamarind pods are caused by breakage of the shell (Jarimopas
and Sirisawas, 2006) in such a way that the broken piece of
shell is missing, and the inside flesh is exposed. The color of the
flesh typically is dark brown, which contrasts with the light brown
or grey of the shell. Fig. 8 shows the grey scale of a defective sweet
tamarind. From this, by using Eqs. (2) and (3), the image of white
pod and black flesh was obtained. Grey color was further added
to the pod to clearly distinguish the environment (in this case,
the white conveyor belt) from the pod and flesh. The size of the defect
could be quantified as follows: