TY - GEN
T1 - A new approximation method of the quadratic discriminant function
AU - Omachi, Shin'ichiro
AU - Sun, Fang
AU - Aso, Hirotomo
PY - 2000
Y1 - 2000
N2 - For many statistical pattern recognition methods, distributions of sample vectors are assumed to be normal, and the quadratic discriminant function derived from the probability density function of multivariate normal distribution is used for classification. However, the computational cost is O(n2) for n-dimensional vectors. Moreover, if there are not enough training sample patterns, covariance matrix can not be estimated accurately. In the case that the dimensionality is large, these disadvantages markedly reduce classification performance. In order to avoid these problems, in this paper, a new approximation method of the quadratic discriminant function is proposed. This approximation is done by replacing the values of small eigenvalues by a constant which is estimated by the maximum likelihood estimation. This approximation not only reduces the computational cost but also improves the classification accuracy.
AB - For many statistical pattern recognition methods, distributions of sample vectors are assumed to be normal, and the quadratic discriminant function derived from the probability density function of multivariate normal distribution is used for classification. However, the computational cost is O(n2) for n-dimensional vectors. Moreover, if there are not enough training sample patterns, covariance matrix can not be estimated accurately. In the case that the dimensionality is large, these disadvantages markedly reduce classification performance. In order to avoid these problems, in this paper, a new approximation method of the quadratic discriminant function is proposed. This approximation is done by replacing the values of small eigenvalues by a constant which is estimated by the maximum likelihood estimation. This approximation not only reduces the computational cost but also improves the classification accuracy.
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U2 - 10.1007/3-540-44522-6_62
DO - 10.1007/3-540-44522-6_62
M3 - Conference contribution
AN - SCOPUS:23044523667
SN - 3540679464
SN - 9783540679462
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 601
EP - 610
BT - Advances in Pattern Recognition - Joint IAPR International Workshops, SSPR 2000 and SPR 2000, Proceedings
A2 - Ferri, Francesc J.
A2 - Inesta, Jose M.
A2 - Amin, Adnan
A2 - Pudil, Pavel
PB - Springer Verlag
T2 - 8th Meeting of the International Workshop on Structural and Syntactic Pattern Recognition, SSPR 2000 and 3rd International Workshop on Statistical Techniques in Pattern Recognition, SPR 2000
Y2 - 30 August 2000 through 1 September 2000
ER -