We introduce two kinds of quasi-inner functions. Since every rationally invariant subspace for a shift operator SK on a vector-valued Hardy space H(Ω, K) is generated by a quasi-inner function, we also provide relationships of quasi-inner functions by comparing rationally invariant subspaces generated by them. Furthermore, we discuss fundamental properties of quasi-inner functions, and quasi-in...

Discrete autocorrelation wavelets have recently been applied in the statistical analysis of locally stationary time series. This form of time series analysis also requires the construction of the inner product matrix of such wavelets. To date, both discrete autocorrelation wavelets and the inner product matrix have been constructed via a brute force technique which proves to be computationally ...

noise, sensitivity, digital cameras, scanners, color, colour We formalize ideas of orthogonality and inner products implicit in the development of a number of figures of merit (FOM, [1]) of colour recording filters. We show that, in negligible measurement noise, the data dependence of each FOM based on linear colour correction is equivalent to a choice of inner product (and hence of orthogonali...

Definition 1. An inner product on a complex vector space V is a map 〈., .〉 : V × V → C such that (i) 〈., .〉 is linear in the first slot: 〈c1v1 + c2v2, w〉 = c1〈v1, w〉+ c2〈v2, w〉, c1, c2 ∈ C, v1, v2, w ∈ V, (ii) 〈., .〉 is Hermitian symmetric: 〈v, w〉 = 〈w, v〉, with the bar denoting complex conjugate, (iii) 〈., .〉 is positive definite: v ∈ V ⇒ 〈v, v〉 ≥ 0, and 〈v, v〉 = 0⇔ v = 0. A vector space with ...