Title
Low Rank Pure Quaternion Approximation For Pure Quaternion Matrices
Abstract
Quaternion matrices are employed successfully in many color image processing applications. In particular, a pure quaternion matrix can be used to represent red, green, and blue channels of color images. A low-rank approximation for a pure quaternion matrix can be obtained by using the quaternion singular value decomposition. However, this approximation is not optimal in the sense that the resulting low-rank approximation matrix may not be pure quaternion, i.e., the low-rank matrix contains a real component which is not useful for the representation of a color image. The main contribution of this paper is to find an optimal rank-r pure quaternion matrix approximation for a pure quaternion matrix (a color image). Our idea is to use a projection on a low-rank quaternion matrix manifold and a projection on a quaternion matrix with zero real component, and develop an alternating projections algorithm to find such optimal low-rank pure quaternion matrix approximation. The convergence of the projection algorithm can be established by showing that the low-rank quaternion matrix manifold and the zero real component quaternion matrix manifold has a nontrivial intersection point. Numerical examples on synthetic pure quaternion matrices and color images are presented to illustrate the projection algorithm can find optimal low-rank pure quaternion approximation for pure quaternion matrices or color images.
Year
DOI
Venue
2021
10.1137/19M1307329
SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS
Keywords
DocType
Volume
color images, pure quaternion matrices, low-rank approximation, manifolds
Journal
42
Issue
ISSN
Citations 
1
0895-4798
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Guang-Jing Song1457.06
Weiyang Ding210.69
Ng Michael34231311.70