Federal
Bureau of Investigation
Method
for
Fingerprint
The subject of wavelets has
become an increasingly popular topic of study in recent years. The number of applications of wavelets is
countless in the fields of mathematics, quantum physics, electrical and nuclear
engineering, geology, astronomy, and even finance. Many new wavelet applications have recently been developed while
interchanging these fields. Some
interesting examples of real life wavelet applications include image
compression, earthquake prediction, musical restoration, turbulence, speech
discrimination, and human vision. The
content of this paper will explore how the Federal Bureau of Investigation
(FBI) uses wavelets in their fingerprint files to compress, transmit, and store
images of millions of fingerprints.
Wavelets are used in areas such as this to process and compress large
amounts of data.
The basic idea of wavelets
is to analyze with respect to scale. A
wavelet is a type of mathematical function that divides up specific data into
components of different frequencies, and then analyzes each component with a
specific resolution according to the scale of the frequency. In much the same way as Riemann Sums are
used to approximate an area under a curve, wavelets can be used to approximate
different types of functions, and the more iterations or steps used in the
calculation, the better the resolution becomes.
Because of their ability to greatly compress large images or
signals, wavelets can be used to represent other functions, especially
functions that are much to large and difficult to work with. Compression using wavelets is often lossy,
which means that compression cannot be reversed and all the original data may
not be reproduced. However, the lost
data is often very small or insignificant in relation to the signal as a
whole. To minimize lost data and to
better approximate a signal, different so-called families of wavelets can be
used. The Haar wavelets and the
Daubechies wavelets are the most common wavelet families. The different types of wavelet families
allows the user to select which set of wavelets would be the best and most
appropriate for a specific application.
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Kalyn Gzym and Todd Frazee designed this web page for a semester project in
Fall 2001. It is based on the report
they wrote while
attending Grand Valley State University, Allendale, MI USA. Any information that may be of help to you
in study and research is encouraged.