A Dynamic Programming Solution to Bounded Dejittering Problems

We propose a dynamic programming solution to image dejittering problems with bounded displacements and obtain efficient algorithms for the removal of line jitter, line pixel jitter, and pixel jitter.Comment: The final publication is available at link.springer.co

Adaptive deinterlacing of video sequences using motion data

In this work an efficient motion adaptive deinterlacing method with considerable improvement in picture quality is proposed. A temporal deinterlacing method has a high performance in static images while a spatial method has a better performance in dynamic parts. In the proposed deinterlacing method, a motion adaptive interpolator combines the results of a spatial method and a temporal method based on motion activity level of video sequence. A high performance and low complexity algorithm for motion detection is introduced. This algorithm uses five consecutive interlaced video fields for motion detection. It is able to capture a wide range of motions from slow to fast. The algorithm benefits from a hierarchal structure. It starts with detecting motion in large partitions of a given field. Depending on the detected motion activity level for that partition, the motion detection algorithm might recursively be applied to sub-blocks of the original partition. Two different low pass filters are used during the motion detection to increase the algorithm accuracy. The result of motion detection is then used in the proposed motion adaptive interpolator. The performance of the proposed deinterlacing algorithm is compared to previous methods in the literature. Experimenting with several standard video sequences, the method proposed in this work shows excellent results for motion detection and deinterlacing performance

Fundamental schemes to determine disjoint paths for multiple failure scenarios

Disjoint path routing approaches can be used to cope with multiple failure cenarios. This can be achieved using a set of k (k>2) link- (or node-) disjoint path pairs (in single-cost and multi-cost networks). Alternatively, if Shared Risk Link Groups (SRLGs) information is available, the calculation of an SRLG-disjoint path pair (or of a set of such paths) can protect a connection against the joint failure of the set of links in any single SRLG. Paths traversing disaster-prone regions should be disjoint, but in safe regions it may be acceptable for the paths to share links or even nodes for a quicker recovery. Auxiliary algorithms for obtaining the shortest path from a source to a destination are also presented in detail, followed by the illustrated description of Bhandari’s and Suurballe’s algorithms for obtaining a pair of paths of minimal total additive cost. These algorithms are instrumental for some of the presented schemes to determine disjoint paths for multiple failure scenarios.info:eu-repo/semantics/publishedVersio

{HDR} Denoising and Deblurring by Learning Spatio-temporal Distortion Model

We seek to reconstruct sharp and noise-free high-dynamic range (HDR) video from a dual-exposure sensor that records different low-dynamic range (LDR) information in different pixel columns: Odd columns provide low-exposure, sharp, but noisy information; even columns complement this with less noisy, high-exposure, but motion-blurred data. Previous LDR work learns to deblur and denoise (DISTORTED->CLEAN) supervised by pairs of CLEAN and DISTORTED images. Regrettably, capturing DISTORTED sensor readings is time-consuming; as well, there is a lack of CLEAN HDR videos. We suggest a method to overcome those two limitations. First, we learn a different function instead: CLEAN->DISTORTED, which generates samples containing correlated pixel noise, and row and column noise, as well as motion blur from a low number of CLEAN sensor readings. Second, as there is not enough CLEAN HDR video available, we devise a method to learn from LDR video in-stead. Our approach compares favorably to several strong baselines, and can boost existing methods when they are re-trained on our data. Combined with spatial and temporal super-resolution, it enables applications such as re-lighting with low noise or blur

08291 Abstracts Collection -- Statistical and Geometrical Approaches to Visual Motion Analysis

From 13.07.2008 to 18.07.2008, the Dagstuhl Seminar 08291 ``Statistical and Geometrical Approaches to Visual Motion Analysis\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general

Conception de processeurs spécialisés pour le traitement vidéo en temps réel par filtre local

RÉSUMÉ Ce mémoire décrit les travaux visant à explorer les possibilités qu'offrent les processeurs à jeu d'instructions spécialisé pour des applications de vidéo numérique. Spécifiquement une classe particulière d'algorithmes de traitement vidéo est considérée: les filtres locaux. Pour cette classe d'algorithmes, une exploration architecturale a permis d'identifier un ensemble de techniques formant une approche cohérente et systématique pour la conception de processeurs spécialisés performants adaptés au traitement vidéo en temps réel. L'approche de conception proposée vise une utilisation efficace de la bande passante vers la mémoire, laquelle bande passante constitue le goulot d'étranglement de l'application du point de vue de la vitesse de traitement. Il est possible d'approcher la performance limite imposée par ce goulot par une stratégie appropriée de réutilisation des données et en exploitant le parallélisme des données inhérent à la classe d'algorithmes visée. L'approche comporte quatre étapes: tout d'abord, une instruction parallèle (SIMD) qui effectue le calcul de plusieurs pixels de sortie à la fois est créée. Puis, des registres à décalage permettant la réutilisation intra-ligne des pixels d'entrée sont ajoutés. Ensuite, un pipeline est créé par le découpage de l'instruction parallèle et l'ajout de registres pour les résultats intermédiaires. Finalement, les instructions spécialisées de chargement et de sauvegarde sont créées. Quelques-unes de ces étapes ouvrent la porte à des simplifications matérielles spécifiques pour certains algorithmes de la classe cible. La structure matérielle obtenue au final, alliée à la parallélisation des instructions par l'utilisation d'une architecture VLIW, se comporte d'une manière semblable à un réseau systolique pipeliné. Afin de démontrer expérimentalement la validité de l'approche de conception proposée, sept processeurs spécialisés pour des algorithmes de la classe visée ont été conçus par extension du jeu d'instructions d'un processeur configurable à jeu d'instructions extensible. Trois de ces processeurs spécialisés mettent en œuvre autant d'algorithmes de désentrelacement intra-trames, et quatre visent plutôt la convolution 2D, différant entre eux par la taille de la fenêtre de convolution. Les résultats de performance obtenus sont prometteurs. Pour les algorithmes de désentrelacement intra-trames, les facteurs d'accélération varient entre 95 et 1330, alors que les facteurs d'amélioration du produit temps-surface varient entre 29 et 243, tout ceci par rapport à un processeur d'usage général de référence roulant une implémentation purement logicielle de l'algorithme.----------ABSTRACT This master thesis explores the possibilities offered by Application-Specific Instruction-Set Processors (ASIP) for digital video applications, more specifically for a particular algorithm class used for video processing: local neighbourhood functions. For this algorithm class, an architectural exploration lead to the identification of a set of design techniques which, together, form a coherent and systematic approach for the design of high performance ASIPs usable for real-time video processing. The proposed design approach aims at an efficient utilization of available bandwidth to memory, which constitutes the main performance bottleneck of the application. It is possible to approach the processing speed limit imposed by this bottleneck through an appropriate data reuse strategy and by exploiting the data parallelism inherent to the target algorithm class. The design approach comprises four steps: first, a Single Instruction Multiple Data (SIMD) instruction which calculates more than one pixel in parallel is created. Then, shift registers, which are used for intra-line input pixel reuse, are added. Next, a processing pipeline is created by the addition of application-specific registers. Finally, the custom load/store instructions are created. Some of these steps lead to possible hardware simplifications for some algorithms of the target class. The hardware structure thus obtained, together with the instruction-level parallelism made possible through the use of a Very Long Instruction Word (VLIW) architecture, mimics a pipelined systolic array. In order to demonstrate the validity of the proposed design approach experimentally, seven ASIPs have been designed by extending the instruction-set of a configurable and extensible processor. Three of the ASIPs implement intra-field deinterlacing algorithms, and four implement the 2D convolution with different kernel sizes. The results show a significant improvement in performance. For the intra-field deinterlacing algorithms, speedup factors are between 95 and 1330, while the factors of improvement of the Area-Time (AT) product are between 29 and 243, all this compared to a pure software implementation running on a general-purpose processor. In the case of the two-dimensional convolution, speedup factors are between 36 and 80, while factors of improvement of the AT product are between 12 and 22. In all cases, real-time processing of high definition video in the 1080i (deinterlacing) or 1080p (convolution) format is possible given a 130 nm manufacturing process

HDTV transmission format conversion and migration path

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (leaves 77-79).by Lon E. Sunshine.Ph.D

Mobility of Nano-Particles in Rock Based Micro-Models

A confocal micro-particle image velocimetry (C-μPIV) technique along with associated post-processing algorithms is detailed for obtaining three dimensional distributions of nano-particle velocity and concentrations at select locations of the 2.5D (pseudo 3D) Poly(methyl methacrylate) (PMMA) and ceramic micro-model. The designed and fabricated 2.5D micro-model incorporates microchannel networks with 3D wall structures with one at observation wall which resembles fourteen morphological and flow parameters to those of fully 3D actual reservoir rock (Boise Sandstone) at resolutions of 5 and 10 μm in depth and 5 and 25 μm on plane. In addition, an in-situ, non-destructive method for measuring the geometry of low and high resolution PMMA and ceramic micro-models, including its depth, is described and demonstrated. The flow experiments use 860 nm and 300 nm fluorescence-labeled polystyrene particles, and the data is acquired using confocal laser scanning microscopy. Regular fluorescence microscopy is used for the in-situ geometry measurement along with the use of Rhodamine dye and a depth-to-fluorescence-intensity calibration, which is linear. Monochromatic excitation at a wavelength of 544 nm (green) produced by a HeNe continuous wave laser was used to excite the fluorescence-labeled nanoparticles emitting at 612 nm (red). Confocal images were captured by a highly sensitive fluorescence detector photomultiplier tube. Results of detailed three dimensional velocity, particle concentration distributions, and particle deposition rates from experiments conducted at flow rates of 0.5 nL/min, 1 nL/min, 10 nL/min and 100 nL/min are presented and discussed. The three dimensional micro-model geometry reconstructed from fluorescence data is used as the computational domain to conduct numerical simulations of the flow in the as-tested micro-model for comparisons to experimental results using dimensionless Navier-Stokes model. The flow simulation results are also used to qualitatively compare with velocity distributions of the flowing particles at selected locations. The comparison is qualitative because the particle sizes used in these experiments may not accurately follow the flow itself given the geometry of the micro-models. These larger particles were used for proof of concept purposes, and the techniques and algorithms used permit future use of particles as small as 50 nm