BREAKPOINT DEPENDENT SCALABLE CODING OF OPTICAL FLOW VOLUME

Motion representations that describe motion flow from one single anchor frame to multiple reference frames can be useful for many tasks such as motion compensation (MC) and frame-rate up-sampling. We construct an anchored, multi-flow representation which we refer to as an Optical Flow Volume (OFV). We explore the use of recent breakpoint dependent DWT (BD-DWT) being considered as part of extensions to JPEG 2000 for coding discontinuous media. Breakpoints describe discontinuity boundary geometry and we estimate a single set of breakpoints that can be shared by all individual flows of the OFV. Additionally, as flows are anchored at a common frame, we are able to readily explore inter-flow transforms. Rate scalable results show significant rate-distortion gains for BD-DWT over the 5/3 DWT commonly used with JPEG 2000. The validity and utility of OFV coding are confirmed with accompanying MC results

JPIP Proxy Server for Remote Browsing of JPEG2000 Images

The JPEG2000 image compression standard offers scalability features in support of remote browsing applications. In particular Part 9 of the JPEG2000 standard defines a protocol called JPIP for interactivity with JPEG2000 code-streams and files. In client-server application based on JPIP, a client does not directly interact with the compressed file, but formulates requests using a simple syntax which identifies the current ldquoFocus Windowrdquo. In this kind of application particularly useful could be a proxy server, that potentially can improve the performance of the system through a better use of the network infrastructure. The aim of this work is to propose a proxy server with JPIP capabilities and shows the benefits that can be brought to remote browsing applications

Scalable Compression of Deep Neural Networks

Deep neural networks generally involve some layers with mil- lions of parameters, making them difficult to be deployed and updated on devices with limited resources such as mobile phones and other smart embedded systems. In this paper, we propose a scalable representation of the network parameters, so that different applications can select the most suitable bit rate of the network based on their own storage constraints. Moreover, when a device needs to upgrade to a high-rate network, the existing low-rate network can be reused, and only some incremental data are needed to be downloaded. We first hierarchically quantize the weights of a pre-trained deep neural network to enforce weight sharing. Next, we adaptively select the bits assigned to each layer given the total bit budget. After that, we retrain the network to fine-tune the quantized centroids. Experimental results show that our method can achieve scalable compression with graceful degradation in the performance.Comment: 5 pages, 4 figures, ACM Multimedia 201

JPEG Pleno Light Field Encoder with Mesh based View Warping

We introduce mesh-based view warping to the JPEG Pleno light field coding framework and replace the standardized sample-based forward warping and splatting of reference texture with mesh-based backward warping, which allows for a more disciplined interpolation of the reference texture for predicting the target view. Instead of coding depth maps with JPEG 2000, which is the default option of the JPEG Pleno framework, we employ a recent extension referred to as JPEG 2000 Part 17. This extension utilises breakpoints to describe discontinuity boundary geometry for the purpose of modifying the predict and update lifting steps in the vicinity of detected discontinuities. We directly decode breakpoints and corresponding DWT coefficients onto a mesh and describe a scheme to construct a single, consolidated mesh for a large group of views, borrowing information from multiple coded depth maps. Results show that the cumulative impact of all these modifications enable improved rate-distortion performance in comparison with the default operation of the JPEG Pleno encoder

The Legal Character and Practical Implementation of a TRIPS Waiver for COVID-19 Vaccines

Almost two years after initial proposals for a COVID-19 waiver of TRIPS obligations, a Ministerial decision adopted at the 12th Ministerial Conference in June 2022 waived obligations under Article 31(f) and the System for pharmaceutical export under the TRIPS Annex, and clarified existing options under TRIPS for increasing access to COVID-19 vaccines. As support for a more expansive pandemic waiver continues and WTO waivers remain legitimate mechanisms under WTO law, further waivers may be contemplated as viable options to address obstacles identified in the current pandemic or future health crises. This article explores what additional options are or may be open to Members under a COVID-19 waiver in its current or proposed forms, and the practical considerations for implementing them. To guide practical choices in selecting appropriate and adapted responses to public health and other crises, this article also investigates more theoretical questions about the nature of a waiver, its legal character and effect, and its interaction with other international agreements

JPEG 2000 Extensions for Scalable Coding of Discontinuous Media

In this paper we propose novel extensions to JPEG 2000 for the coding of discontinuous media which includes piecewise smooth imagery such as depth maps and optical flows. These extensions use breakpoints to model discontinuity boundary geometry and apply a breakpoint dependent Discrete Wavelet Transform (BP-DWT) to the input imagery. The highly scalable and accessible coding features provided by the JPEG 2000 compression framework are preserved by our proposed extensions, with the breakpoint and transform components encoded as independent bit streams that can be progressively decoded. Comparative rate-distortion results are provided along with corresponding visual examples which highlight the advantages of using breakpoint representations with accompanying BD-DWT and embedded bit-plane coding. Recently our proposed extensions have been adopted and are in the process of being published as a new Part 17 to the JPEG 2000 family of coding standards

Generating continuous variable quantum codewords in the near-field atomic lithography

Recently, D. Gottesman et al. [Phys. Rev. A 64, 012310 (2001)] showed how to encode a qubit into a continuous variable quantum system. This encoding was realized by using non-normalizable quantum codewords, which therefore can only be approximated in any real physical setup. Here we show how a neutral atom, falling through an optical cavity and interacting with a single mode of the intracavity electromagnetic field, can be used to safely encode a qubit into its external degrees of freedom. In fact, the localization induced by a homodyne detection of the cavity field is able to project the near-field atomic motional state into an approximate quantum codeword. The performance of this encoding process is then analyzed by evaluating the intrinsic errors induced in the recovery process by the approximated form of the generated codeword.Comment: 9 pages, 5 figure

Analyzing Scheduling Performance for Real-time Traffic in Wireless Networks

This paper is a sequel to an earlier study on scheduling real-time traffic in wireless TDMA channels. In particular, we develop mathematical analysis to model the system behavior of the equal-delay scheme and its extension of the multi-class scheme, both of which were proposed previously. The main usefulness of the proposed scheduling mechanisms is the improvement on the worst-case delay, and consequently the reduction in probability of delay violation or loss. We achieve the analytical solution by evaluating the corresponding cumulative distribution of delay. The derivation of the distribution function is based on a well-known method of solving a set of first order differential equations and eliminating all unstable modes. However, the existence of channel variations generate unique difficulties which renders the original method unsuitable. To solve this problem, we devise novel transformation techniques and an algorithm to recursively estimate the state probabilities in steady-state, so the original method can be applied in an alternative manner. Furthermore, we develop a reduced state model for homogeneous systems to alleviate the requirement on computational complexity of the full model. On the other hand, an additional challenge to extend the mathematical model to support the multi-class system is to overcome the varying progression rates of individual transmissions. To tackle this problem, we model the system aggregate delay value and recalculate the scaled statistics for each class of flows according to their pre-assigned weights. Finally, numerical results and computational complexity analysis are presented

Squashed States of Light: Theory and Applications to Quantum Spectroscopy

Using a feedback loop it is possible to reduce the fluctuations in one quadrature of an in-loop field without increasing the fluctuations in the other. This effect has been known for a long time, and has recently been called ``squashing'' [B.C. Buchler et al., Optics Letters {\bf 24}, 259 (1999)], as opposed to the ``squeezing'' of a free field in which the conjugate fluctuations are increased. In this paper I present a general theory of squashing, including simultaneous squashing of both quadratures and simultaneous squeezing and squashing. I show that a two-level atom coupled to the in-loop light feels the effect of the fluctuations as calculated by the theory. In the ideal limit of light squeezed in one quadrature and squashed in the other, the atomic decay can be completely suppressed.Comment: 8 pages plus one figure. Submitted to JEOS-B for Dan Walls Special Issu