Its a demonstration for the first version of Silent Keyboard idea.
The main idea came from a project called Silent Drum.
The performer put her finger on the black sheet and make a contour with some local extrema. then a software captures the image in real time finds the contour and the extrema. it then sends this data to a synthesizer/filter as its parameters.
I wrote the computer vision part with OpenCV libraries in C# and made a sample synthesizer with PureData. their connection is through local TCP port.
This device could be used as a continuous frequency keyboard with varying volume or harmonics of each note, a traditional discrete frequency keyboard, or a low/band/high pass filter.