This paper presents a new moment-preserving thresholding technique, called the binary quaternion-moment-preserving (BQMP) thresholding, for color image data. Based on representing color data by the quaternions, the statistical parameters of color data can be expressed through the definition of quaternion moments. Analytical formulas of the BQMP thresholding can thus be determined by using the a...

Using the ideas and techniques developed by Bayer-Fluckiger, Shapiro and Tignol about hyperbolic involutions of central simple algebras, criteria for the hyperbolicity of involutions of the form σ⊗ τ and σ⊗ ρ, where σ is an involution of a central simple algebra A, τ is the nontrivial automorphism of a quadratic extension of the center of A and ρ is an involution of a quaternion algebra are obt...

A novel quaternion color representation tool is proposed to the images and videos efficiently. In this work, we consider a full model for representation and processing color images in the quaternion algebra. Color images are presented in the threefold complex plane where each color component is described by a complex image. Our preliminary experimental results show significant performance impro...

The level of a ring R with 1 6= 0 is the smallest positive integer s such that −1 can be written as a sum of s squares in R, provided −1 is a sum of squares at all. D.W. Lewis showed that any value of type 2n or 2n + 1 can be realized as level of a quaternion algebra, and he asked whether there exist quaternion algebras whose levels are not of that form. Using function fields of quadratic forms...

Let O be a maximal order in a definite quaternion algebra over Q of prime discriminant p, and ` a small prime. We describe a probabilistic algorithm, which for a given left O-ideal, computes a representative in its left ideal class of `-power norm. In practice the algorithm is efficient, and subject to heuristics on expected distributions of primes, runs in expected polynomial time. This breaks...

Let D be a positive definite quaternion algebra over a totally real number field K, F (X, Y ) a hermitian form in 2N variables over D, and Z a right D-vector space which is isotropic with respect to F . We prove the existence of a small-height basis for Z over D, such that F (X, X) vanishes at each of the basis vectors. This constitutes a non-commutative analogue of a theorem of Vaaler [19], an...

1. Formulae for genera, volumes, class numbers Throughout these notes, we shall use D to denote the product of an even number (possibly zero) of distinct primes, and D′ the product of an odd number of distinct primes. Thus D (resp. D′) is the discriminant of a unique indefinite (resp. definite) rational quaternion algebra B/Q of discriminant D (resp. D′). Recall that the discriminant map induce...

Geometric algebra is a useful tool to overcome some problems in kinematics. Thus, the geometric has attracted attention of many researchers. In this paper, quaternion operators on curves and surfaces Euclidean 3-space are defined by using algebra. These generate or from points, surfaces. Using operators, we obtain motions that have orbits along generated curve surface. Also, these expressed as ...

It is well-known that every two dimensional rotation around the origin in the plane R can be represented by the multiplication of the complex number e = cos θ + i sin θ, 0 ≤ θ < 2π. Similarly, every three dimensional rotation in the space R can be represented by the multiplications of the quaternion q from the left-hand side and its conjugate q̄ from the right-hand side, where q = cos(θ/2) + α s...