Multimodal Multilingual Biometric Database 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The database is composed of:
	* signatures
	* video: 
		+ audio 
		+ still pictures

Audio and still pictures are generated from the video files with perl
scripts and mplayer (http://www.mplayerhq.hu/) software.

Signatures:
~~~~~~~~~~~

Fake or modified signatures were collected and saved in files with .dat
extension. Singature files are composed of comma separated integer
values, with:

X,Y,pressure,time 

denoted X,Y,P,T from now on.

X can take values in the interval of 0 to 1xxxx.
Y can take values in the interval of 0 to 7yyy.
P can take values in the interval of 0 to 511.
T is measured in ms and always starts on 0.

Pen ups are denoted with X=-1,Y=-1,P=-1, and arbitrary T value, take this
into account when building statistical models, because X=-1,Y=-1 is not a
"real" spatial coordinate of the signature.

 * Capturing Device:

Wacom "Graphire3 4x5" digitizer tablet. Sensing surface 127.6mm x 92.8mm.
Spatial reolution is 2032 lpi (lines per inch). 512 different pressure
levels. Sampling rate is about 100Hz (varying).
http://www.wacom.com/graphire/4x5.cfm


Audio and Video
~~~~~~~~~~~~~~~

The videos provide audio and still pictures.  Video is encoded raw UYVY.
AVI 640 x 480, 15.00 fps with uncompressed 16bit PCM audio; mono, 32000
Hz. A few videos are with uncompressed PCM audio; stereo, 44100 Hz
little endian. 

Audio:
~~~~~~

Audio is extracted as 16 bit PCM WAV file (with wav header), sampled at
16000 Hz, mono little endian.

BUGS: there is a problem with mplayer not writting the byte_alignment of
the wav header correctly, which causes files not being read correctly on
matlab, this is a value which is not commonly used, but matlab does. A
patch fixing the bug was sent to mplayer developers, but as of now it
doesn't have been included yet. We include the patch with the database.
Against Repository revision: 1.29 of /cvsroot/mplayer/main/libao2/ao_pcm.c
The patch should also work against MPlayer-1.0pre7.

 * Capturing Device:

Shure SM58 microphone. Frequency response 50 Hz to 15000 Hz. Unidirectional
(Cardiod) dynamic vocal microphone.

Still Pictures
~~~~~~~~~~~~~~

There are perl scripts for extraction of audio and still pictures from the
videos, extraction of audio takes significantly less time than picture
extraction.

Uncompressed PNG (portable network graphics) files are extracted from the video files.

 * Capturing Device:

Allied Vision Technologies AVT marlin MF-046C 10 bit ADC, 1/2" (8mm) Progressive scan SONY IT CCD
http://www.alliedvisiontec.com/indexc.php?p=91&t=produktinfos&o=3&a=sp


		
