The system is designed for patients to control mouse cursor
by waving hand, which mean the hand tracking is focused on
hand palm rather than hand wrist and forearm. This stage
included the removing of unnecessary part and tracks the
centroid of hand palm region. In the example of [19], the
centroid or called centre of gravity by author is directly
applied to the hand image. However, a real time control
movement will be affected by using the same method. This
method is infeasible as the centroid is tracked throughout the
connected component. As a user move the hand upward, the
height of object increased, overall centre point will be
remained at certain height result in limited movement of
mouse cursor. The separation of hand palm region can be
achieved by finding largest inner circle in the white area.
Considering the width from whole structure of hand, we
assume highest possibility to illustrate largest inner circle must
be in hand palm region, less likely to be neither forearm nor
fingers. We used the method called morphological structural
element combined with bottom-hat filter[20].