Abdelghani Ghomari

Events Detection Using a Video-Surveillance Ontology and a Rule-Based Approach

In this paper, we propose the use of a Video-surveillance Ontology and a rule-based approach to detect an event. The scene is described using the concepts presented in the ontology. Then, the blobs are extracted from the video stream and are represented using the bounding boxes that enclose them. Finally, a set of rules have been proposed and have been applied to videos selected from PETS 2012 challenge that contain multiple objects events (e.g. Group walking, Group splitting, etc.).

An approach for synchronization and management of multimedia scenarios in an object-oriented database

In this paper we will present an approach for multimedia scenario management in a database system that considers: an object-oriented method for multimedia scenarios modeling; time-interval and causal relations models for the specification of known and unknown multimedia object playing duration; temporal specification language; time Petri net automatic generation based on temporal specifications; and finally automatic detection of user temporal specification errors and contradictions.

Temporal and Spatial Coherence Verification in SMIL Documents with Hoare Logic and Disjunctive Constraints: A Hybrid Formal Method

The challenging problem of formal verification of SMIL (Synchronized Multimedia Integration Language Specification) documents is considered in this paper, where we propose a hybrid formal method that automatically detects and corrects the temporal and spatial conflicts. The proposed solution is based on a related work that uses Hoare logic for temporal conflict detection in SMIL documents. The use of Hoare logic is borrowed by that solution but with many improvements and extensions. New rules are added to enable modeling of more SMIL elements. We also deal with spatial conflicts and propose a spatio-temporal inconsistencies verification algorithm, called Spatio-temporal Inconsistencies Verification Algorithm (SIVA), that checks the spatial incoherence of SMIL documents. The disjunctive constraints of Marriott are used to correct the spatial inconsistencies. Furthermore, we propose a new tool that helps the author to validate the temporal and spatial constraints in SMIL documents. If any temporal or spatial conflicts are detected, the system returns a help message to report the error and help the author to correct the conflict. Finally, our contribution has been compared with two recent related works, and the results show that the proposed solution allow to check more attributes.

OVIS: ontology video surveillance indexing and retrieval system

Nowadays, the diversity and large deployment of video recorders result in a large volume of video data, whose effective use requires a video indexing process. However, this process generates a major problem consisting in the semantic gap between the extracted low-level features and the ground truth. The ontology paradigm provides a promising solution to overcome this problem. However, no naming syntax convention has been followed in the concept creation step, which constitutes another problem. In this paper, we have considered these two issues and have developed a full video surveillance ontology following a formal naming syntax convention and semantics that addresses queries of both academic research and industrial applications. In addition, we propose an ontology video surveillance indexing and retrieval system (OVIS) using a set of semantic web rule language (SWRL) rules that bridges the semantic gap problem. Currently, the existing indexing systems are essentially based on low-level features and the ontology paradigm is used only to support this process with representing surveillance domain. In this paper, we developed the OVIS system based on the SWRL rules and the experiments prove that our approach leads to promising results on the top video evaluation benchmarks and also shows new directions for future developments.

Probe-SDN: A smart monitoring framework for SDN-based networks

Software Defined Networking (SDN) is in the process of revolutionizing the way of managing networks by providing a new way to support current and future services. However, by relocating the control functionality in a remote entity, the measurements accuracy of the resources utilization becomes more difficult, which complicates the decision making. Although there are previous works focusing on the problem of network management and measurement in SDN networks, only few proposed solutions have taken into consideration the tradeoff existing between statistics polling frequency (i.e. generated overhead), and the accuracy of monitoring results (i.e. optimized resources allocation). In this paper, we propose a new approach calculating accurately the bandwidth utilization while adapting the polling frequency according to ports/switches activity. The emulations results under Mininet clearly demonstrate the effectiveness of the proposed solution, which outperforms existing works.

Videoconferencing over OpenFlow Networks: An Optimization Framework for QoS Routing

The recent emergence of OpenFlow, in the field of networks control, marks a major evolution in networking. Indeed, Openflow comes up with a centralized control plane (real or virtual) and a remote control of the data plan, which enable networks evolution with unprecedented rapidity. This evolution, come, however, with new challenges and open issues. The data path portion still resides on networking devices, while high-level routing decisions are moved to a separate remote server, which may impact the QoS of the supported services. Particularly, there is a need to guarantee at least the QoS that was formally provided using older and classical distributed protocols. This paper focuses on an improvement of the traditional OpenFlow controllers by providing QoS Routing support for Videoconferencing over OpenFlow networks. The simulation results under Mininet clearly demonstrate the effectiveness of the proposed approach.

An ontology based approach for inferring multiple object events in surveillance domain

The ontology is an efficient tool that can bridge the semantic gap between the extracted information from the visual data and its interpretation in a given context. The ontology has been used in video surveillance applications to improve the accuracy of the indexing and retrieval system. However, these systems handle only one or two objects without considering events that involve multiple objects. In this paper, we propose to use OVIS (Ontology based Video surveillance Indexing and retrieval System) a system for indexing and retrieving videos in video surveillance application. We have applied OVIS to videos that contain multiple objects events (e.g. Group walking, Group splitting, Group formation, etc.).

Retracted: Towards a Formal Approach for Verifying Temporal Coherence in a SMIL Document Presentation

In this paper we will present an approach based on Time Petri net TPN for verifying temporal coherence in a SMIL Synchronized Multimedia Integration Language document presentation. In our approach, we can model a SMIL document by TPN model by translation of the SMIL elements and attributes into TPN concepts. Some extension of the TPN model is made to obtain the synchronization concepts equivalence of a SMIL document like sequential and parallel. The analysis of TPN by the Tina tool allows us to verify the consistency properties and the temporal coherence of the SMIL document.

Modeling Multimedia Synchronization Using a Time Petri Net Based Approach

Multimedia refers to the presentation of collections of both static and dynamic data (i.e., data with natural time dependencies e.g., audio or video) in a specified order and time. Therefore, their mutual synchronization must assure a proper temporal order of presentation events. Multimedia synchronization can be defined as a mutual assignment of data items and time instants. These time instants may be known in advance (e.g., standard consumer data players) or they can be also results of some unknown function of time (event driven synchronization) or known with some limited accuracy (e.g., random network delays). The modelling and the presentation of multimedia scenarios are challenges of multimedia applications. Multimedia scenarios are results of temporal composition and user interactions of multimedia objects in an application domain, and lot of works discussed this notion (Adjeroh & Lee, 1995; Perez-Luque & Little, 1996). Temporal compositions consist in presenting multimedia objects which requires synchronization among different media. Most of specification models are based on Allen’s relations (Allen, 1983). Allen defined seven basic relations between two temporal intervals. For example, a TV program starts at 9:00 pm, and finishes at 11:00 pm. The TV program can be considered as one of multimedia objects. In addition, “interval” is considered as a range from 9:00 pm to 11:00 pm, and “duration” as two hours. Allen’s relations require this duration of the interval. Before designing the specification model, interval duration must be known. This means that multimedia database systems must determine duration of multimedia objects, because presentations are almost dependent of duration. Our approach defines a tool that has two important inter-dependent features: User temporal specification based on an appropriate temporal specification language, which is itself based on an extension of Allen’s temporal relations (Allen, 1983). This extension models both existing temporal arrangement and dependency relations between multimedia objects, and this is an interesting point of our work. Automatic generation of a time Petri net based on the previous temporal specification. The time Petri net is stored in an object called “scenario object”. The user may request the simulation and the interpretation of the scenario object which leads to scenario