In this article, we first review the vector quantiser and discuss its well-known advantages over the scalar quantiser, namely the space-filling advantage, the shape advantage, and the memory advantage. It is important to understand why vector quantisers always perform better than any other quantisation scheme for a given dimension, as this will provide the basis for our investigation on improvi...

A discussion is given of the quantisation of a physical system with finite degrees of freedom subject to a Hamiltonian constraint by treating time as a constrained classical variable interacting with an unconstrained quantum state. This leads to a quantisation scheme that yields a Schrödinger-type equation which is in general nonlinear in evolution. Nevertheless it is compatible with the probab...

We propose in this paper a new method for the quantisation of systems with first-class constraints. This method is a combination of the coherent-state-path-integral quantisation developed by Klauder, with the ideas of reduced state space quantisation. The key idea is that the physical Hilbert space may be defined by a coherent-state path-integral on the reduced state space and that the metric o...

The authors have developed a lossy coding scheme using a 3D discrete cosine transform, for use with integral 3D image data. Correct selection of the step sizes of the uniform symmetric scalar quantisers used in the scheme is crucial to attaining good rate-distortion performance. Imageorientated optimisations have been performed to obtain the quantisation parameters leading to minimum objective ...

For efficient coding of speech, it is desirable to separate the slowly and rapidly evolving spectral components to take advantage of their different perceptual qualities. In this paper, we present a multi-level wavelet decomposition mechanism, using low-delay FIR filters, applied to Waveform Interpolation coding. The technique overcomes the substantial delay problems of [2] and identifies a pre...

Resistive switching offers a promising route to universal electronic memory, potentially replacing current technologies that are approaching their fundamental limits. In many cases switching originates from the reversible formation and dissolution of nanometre-scale conductive filaments, which constrain the motion of electrons, leading to the quantisation of device conductance into multiples of...