Region-adaptive probability model selection for the arithmetic coding of video texture

In video coding systems using adaptive arithmetic coding to compress texture information, the employed symbol probability models need to be retrained every time the coding process moves into an area with different texture. To avoid this inefficiency, we propose to replace the probability models used in the original coder with multiple switchable sets of probability models. We determine the model set to use in each spatial region in an optimal manner, taking into account the additional signaling overhead. Experimental results show that this approach, when applied to H. 264/AVC's context-based adaptive binary arithmetic coder (CABAC), yields significant bit-rate savings, which are comparable to or higher than those obtained using alternative improvements to CABAC previously proposed in the literature

Convolution mixture of FBF and modulated FBF and application to HRTEM images

International audienceIn this paper, we propose a mixture involving a fractional Brownian field and a modulated version of such a field for modeling High Resolution Transmission Electron Microscopy (HRTEM) textures. The mixture under consideration is defined from the convolution operator applied on spatial variables of the two fields under consideration. We present estimation methods for the parameters of the model (2 Hurst parameters and 2 spectral poles) based on Wavelet Packet (WP) spectrum. The relevance of our method is highlighted by its application to the analysis of HRTEM images with active phases of a catalyst.Dans cet article, nous proposons de modéliser certaines textures apparaissant dans les images à Haute Résolution de Microscopie Electronique en Transmission (HRMET) à l'aide d'un mélange composé d'un champ Brownien fractionnaire avec une version modulée d'un tel champ. Le mélange en question est basé sur un opérateur de convolution s'appliquant sur les variables spatiales des deux champs considérés. Nous présentons deux méthodes d'estimation des paramètres de Hurst du modèle en utilisant une approche par ondelettes. Nous présentons également une méthode pour localiser les pôles du modèle. Nous montrons la pertinence de ce modèle en l'appliquant à l'analyse des images HRMET contenant des phases actives d'un catalyseur. Abstract-In this paper, we propose a mixture involving a fractional Brownian field and a modulated version of such a field for modeling High Resolution Transmission Electron Microscopy (HRTEM) textures. The mixture under consideration is defined from the convolution operator applied on spatial variables of the two fields under consideration. We present estimation methods for the parameters of the model (2 Hurst parameters and 2 spectral poles) based on Wavelet Packet (WP) spectrum. The relevance of our method is highlighted by its application to the analysis of HRTEM images with active phases of a catalyst

Report of AhG on Exploration in Wavelet Video Coding

The AHG on Exploration in Wavelet Video Coding [1] was established at the 73rd MPEG meeting in Poznan, Poland, with the following mandates: 1. To identify and describe new applications of wavelet video coding; 2. For such applications, define coding conditions and plan a performance comparison with other codecs; 3. Conduct the exploration experiments; 4. Maintain and validate the exploration reference software; 5. Maintain and edit the wavelet codec reference document. All discussions took place over the reflector, [email protected], i.e., ~ 100 emails have been exchanged. AhG meeting: Saturday October 24th, 14:30-18:30, Nice Acropolis AhG meeting agenda: 1.- review of conducted exploration experiments on wavelet video coding; 2.- review 74th ISO/MPEG meeting input documents of interest to this AhG; 3.- review this AhG mandates and prepare AhG report, includine recommendation

Motion Compensated Video Compression with 3D Wavelet Transform and SPIHT

The following paper introduces a low bitrate video coding method on the basis of 3D motion compensated wavelet transform and SPIHT algorithm. In contrast to the conventional algorithms applying motion compensation and differential coding, here wavelet transform is used to exploit the opportunities of time redundancy. For coefficient collection, the 3D version of SPIHT algorithm was selected from the various procedures developed for wavelet transform. Motion vectors are compressed, too (also by wavelet transform), therefore the time and spatial redundancy of coding is exploited here as well. These procedures result in effective video compressing and can easily be aligned to the MPEG4 standard

On the ergodic convergence rates of a first-order primal-dual algorithm.

International audienceWe revisit the proofs of convergence for a first order primal-dual algorithm for convex optimization which we have studied a few years ago. In particular, we prove rates of convergence for a more general version, with simpler proofs and more complete results. The new results can deal with explicit terms and nonlinear proximity operators in spaces with quite general norms

Adapting Columbus Operations and Providing a Basis for Future Endeavours

On 15th December 2015, Timothy Peake – the 4th ESA astronaut in 20 months – headed into orbit for a 6-month stay on the ISS. The British astronaut's "Principia" mission holds many interesting tasks, not only for Tim Peake himself (he performed an EVA on 15th January 2016) but also for the teams on the ground. One of the most exciting activities was the second session of the Airway Monitoring experiment, which again included an experiment run in the US airlock under coordination of the Columbus Control Centre (Col-CC). Besides that, there were many other experiments, such as EML, PK4, DOSIS and Meteron, and also the transition to new NASA tools (e.g. WebAD) was done in this period. Since the establishment of ESA's new setup in July 2015, Col-CC has been working together with all its partners to define the new interfaces, exploit new possibilities, and define in detail the tasks for the operations teams. Besides the ongoing work to monitor and command Columbus, support the ESA experiments on the ISS, as well as supporting the ESA astronaut himself, Col-CC is looking forward towards potential future tasks and challenges. Based on many years of experience in human space flight, an initial study was launched to investigate some of the challenges of human space flight activities beyond Earth orbit. One of these challenges is the delay of communication transmissions experienced over long distances. Until now, all our human space flight operations have been based on (near) real-time communications to monitor and control the spacecraft. This paper describes the results of our study investigating the necessary changes to current operations in the case of long-distance communications. Example procedures are assessed on their reliance on real-time communications and thus how current operations would be impacted by transmission delays. Methods are proposed to make the procedures tolerant to delays, and enable operations to use these procedures for deep space missions

Reproducible Research in Signal Processing

Reproducible research results become more and more an important issue as systems under investigation are growing permanently in complexity, and it becomes thus almost impossible to judge the accuracy of research results merely on the bare paper presentation.Peer ReviewedPreprin

Medical Image Compression using Lifting based New Wavelet Transforms

In this paper, the construction of new lifting based wavelets by a new method of calculating lifting coefficients is presented. First of all, new basis functions are utilized to ease new orthogonal traditional wavelets. Then by using the decomposing poly-phase matrix the lifting steps are calculated using a simplified method. The interesting feature of lifting scheme is that the construction of wavelet is derived in spatial domain only; hence the difficulty in the design of traditional wavelets is avoided. Lifting scheme was used to generate second generation wavelets which are not necessarily translation and dilation of one particular function. Short and sharp basis functions are chosen so as to obtain the non-uniform nature of usual image classes. Implemented wavelets are applied on a number of medical images. It was found that the compression ratio (CR) and Peak Signal to Noise Ratio (PSNR) are far ahead of that are obtained with the popular traditional wavelets as well as the successful 5/3 and 9/7 lifting based wavelets. Set Partitioning in Hierarchical Trees (SPIHT) is used to incorporate compression.DOI:http://dx.doi.org/10.11591/ijece.v4i5.596