  This work is about the extraction of the motion of fingers, in their three
articulations, of a keyboard player from a video sequence. The relevance of the
problem involves several aspects, in fact, the extraction of the movements of
the fingers may be used to compute the keystroke efficiency and individual
joint contributions, as showed by Werner Goebl and Caroline Palmer in the paper
'Temporal Control and Hand Movement Efficiency in Skilled Music Performance'.
Those measures are directly related to the precision in timing and force
measures. A very good approach to the hand gesture recognition problem has been
presented in the paper ' Real-Time Hand Gesture Recognition Using Finger
Segmentation'. Detecting the keys pressed on a keyboard is a task that can be
complex because of the shadows that can degrade the quality of the result and
possibly cause the detection of not pressed keys. Among the several approaches
that already exist, a great amount of them is based on the subtraction of
frames in order to detect the movements of the keys caused by their pressure.
Detecting the keys that are pressed could be useful to automatically evaluate
the performance of a pianist or to automatically write sheet music of the
melody that is being played.
