28-07-2012, 10:12 AM
GAIT BIOMETRICS
biometric_gait.ppt (Size: 2.64 MB / Downloads: 31)
BIOMETRICS: Definition
Biometrics is the study of methods for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits.
bios = "life", metron ="measure“ (ancient Greek)
WHY BIOMETRICS ?
Only authorized users should access data, places, services
Nowadays identity checking is mainly performed in two ways:
Something one possesses – a "token" (e.g., credit card or document). However, it can be lost or copied
Something one knows, like a password. But, it can be guessed, cracked, or even lost or stolen (if written down).
Advantages:
Uniqueness
No need to remember passwords or carry tokens
Biometrics cannot be lost, stolen or forgotten
More secure than a long password
Solves repudiation problem
Not susceptible to traditional dictionary attacks
Disadvantages:
Violation of privacy ?
Often requires significant computational resources
It cannot be changed: once forged
Accuracy measures:
False Acceptance Rate (FAR) and False Rejection Rate (FRR)
Error rates at different thresholds
Used to set operating threshold
Score Distribution
Frequency of client and imposter scores
Small overlap suggests a good system
MV-BASED GAIT RECOGNITION
Gait is captured using a video-camera from distance
Static body parameters such as the height, the distance between head and pelvis, the maximum distance between pelvis and feet, and the distance between feet are extracted and used them for recognition
Most of the MV-based gait recognition algorithms are based on the human silhouette.
FS-BASED GAIT RECOGNITION
A set of sensors or force plates are installed on the floor
Such sensors enable to measure gait related features, when a person walks on them.
One of the main advantages of FS-based gait recognition is in its unobtrusive data collection.
WS-BASED GAIT RECOGNITION
Gait is collected using body worn motion recording (MR) sensors.
The acceleration of gait, which is recorded by the MR sensor, is utilized for authentication.
One of the main advantages of the WS-based gait recognition over several other biometric modalities is its unobtrusive data collection
CONCLUSION
The primary advantage of MV-based gait biometric is in being captured from the distance.
The main advantages of WS-based and FS-based gait biometric is in providing unobtrusive user authentication and identification.
It is worth noting that we do not consider gait as a replacement for traditional authentication mechanisms (passwords, fingerprints, etc.) but rather a complementary biometric.