uWave and gestureRecognizer


About:

A gesture recognition system that works with accelerometer x/y/z axis data
based on uWave.


History:

I stumbled upon uWave, a gesture recognition system.  While it worked fine it
was not very efficient and the implementation was lacking and hard to follow.

uWave did not support continuous gesture recognition which I need for a project
of mine.  The implementation was certainly not suitable for continuous gesture
recognition due to excessive memory allocation/deallocation, intensive
recursive calculations and excessive i/o operations.

I thus decided to refactor a bit of uWave in order to understand it before
re-implementing it in C++.

The use of static filenames and buffers in the code is because the classes will
be further refactored and re-used on an embedded processor with limited ram and
no file based i/o.


Copyright:

The original uWave code (uWave.h and uWave.c) is copyright of the authors:
http://www.owlnet.rice.edu/~zw3/files/RICE/uWave/uWaveGestureLibraryReadme.html

They say I must include this statement: "Jiayang Liu, Zhen Wang, Lin Zhong, 
Jehan Wickramasuriya, and Venu Vasudevan, "uWave: Accelerometer-based 
personalized gesture recognition and its applications," in Proc. IEEE Int. 
Conf. Pervasive Computing and Communication (PerCom), March 2009."

The re-factored code and my new implementation also require that the above
statement be included if it is re-used in addition to requiring the following
statement:

"This product includes components of gestureRecognizer by Dominic Clifton"

Other than that the GPL v3 applies (See LICENCE)


Setup:

Connect a MPU6050 to a raspberry pi's i2c bus.  Use default MPU6050 address.
Raspberry Pi Model B v2.0 used for development.  i2c device address is
hard-coded in the i2c library.  "/dev/i2c-1"


Build:

To build both executables (uWave and gestureRecognizer) issue:

make

To build just uWave:

make uWave

To build just gestureRecognizer:

make gestureRecognizer


Usage:

Record gestures:

Gestures are always recorded in "record.ges".  Gestures are always 1 second long.

sudo ./gestureRecognizer RECORD
mv record.ges 0.ges
sudo ./gestureRecognizer RECORD
mv record.ges 1.ges
sudo ./gestureRecognizer RECORD
mv record.ges 2.ges

.. and so on.  Max supported gestures is currently 16.  See config.h

Match a single gesture:

sudo ./gestureRecognizer

Continuously match gestures:

sudo ./gestureRecognizer CONTINUOUS

Replay gesture matching:

cp mygesture.ges replay.ges
./gestureRecognizer REPLAY


Notes:

The uWave executable does not have any specific timing, that is it runs as fast
as possible.  This means that any gestures recorded (*.uwv) are not very useful
or re-usable on other machines/systems/etc.

Currently recorded gestures can be imported into gestureRecognizer via the
Gesture::import() method, you would also need to enable USE_QUANTIZER in
Config.h.  The import method will probably be removed at a later date but it is
useful during development to compare results.

It seems that the uWave library mangles the data, see USE_QUANTIZER but the
method of data mangling doesn't lend itself well to the values provided by the
MPU6050.  See the other uWave examples.