841 research outputs found
Generalized Two-Dimensional Quaternion Principal Component Analysis with Weighting for Color Image Recognition
A generalized two-dimensional quaternion principal component analysis
(G2DQPCA) approach with weighting is presented for color image analysis. As a
general framework of 2DQPCA, G2DQPCA is flexible to adapt different constraints
or requirements by imposing norms both on the constraint function and
the objective function. The gradient operator of quaternion vector functions is
redefined by the structure-preserving gradient operator of real vector
function. Under the framework of minorization-maximization (MM), an iterative
algorithm is developed to obtain the optimal closed-form solution of G2DQPCA.
The projection vectors generated by the deflating scheme are required to be
orthogonal to each other. A weighting matrix is defined to magnify the effect
of main features. The weighted projection bases remain the accuracy of face
recognition unchanged or moving in a tight range as the number of features
increases. The numerical results based on the real face databases validate that
the newly proposed method performs better than the state-of-the-art algorithms.Comment: 15 pages, 15 figure
Multispectral Palmprint Recognition Using Textural Features
In order to utilize identification to the best extent, we need robust and
fast algorithms and systems to process the data. Having palmprint as a reliable
and unique characteristic of every person, we extract and use its features
based on its geometry, lines and angles. There are countless ways to define
measures for the recognition task. To analyze a new point of view, we extracted
textural features and used them for palmprint recognition. Co-occurrence matrix
can be used for textural feature extraction. As classifiers, we have used the
minimum distance classifier (MDC) and the weighted majority voting system
(WMV). The proposed method is tested on a well-known multispectral palmprint
dataset of 6000 samples and an accuracy rate of 99.96-100% is obtained for most
scenarios which outperforms all previous works in multispectral palmprint
recognition.Comment: 5 pages, Published in IEEE Signal Processing in Medicine and Biology
Symposium 201
Color Image Analysis by Quaternion-Type Moments
International audienceIn this paper, by using the quaternion algebra, the conventional complex-type moments (CTMs) for gray-scale images are generalized to color images as quaternion-type moments (QTMs) in a holistic manner. We first provide a general formula of QTMs from which we derive a set of quaternion-valued QTM invariants (QTMIs) to image rotation, scale and translation transformations by eliminating the influence of transformation parameters. An efficient computation algorithm is also proposed so as to reduce computational complexity. The performance of the proposed QTMs and QTMIs are evaluated considering several application frameworks ranging from color image reconstruction, face recognition to image registration. We show they achieve better performance than CTMs and CTM invariants (CTMIs). We also discuss the choice of the unit pure quaternion influence with the help of experiments. appears to be an optimal choice
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