CNRS Laboratory of Images and Information Systems Information Technology

Lyon, France

CNRS Laboratory of Images and Information Systems Information Technology

Lyon, France
Time filter
Source Type

Samuel J.,CNRS Laboratory of Images and Information Systems Information Technology | Rey C.,CNRS Laboratory of Informatics, Modeling and Optimization of Systems
2016 11th International Conference on Digital Information Management, ICDIM 2016 | Year: 2016

The use of diverse web services has simplified routine tasks but it has resulted in loss of direct control over the data. This shift from traditional self-controlled databases to heterogeneous, autonomous web services can be increasingly seen among small and medium scale enterprises. Enterprises dependent on web services require a generic approach to integrate with multiple web services. The classical mediation approach from the data integration field provides a uniform query interface to diverse data sources hiding the underlying heterogeneity, but its utilization with current generation web services API has several research and industrial challenges which will be described in this article. © 2016 IEEE.

Digne J.,CNRS Laboratory of Images and Information Systems Information Technology | Valette S.,INSA Lyon | Chaine R.,University Claude Bernard Lyon 1
IEEE Transactions on Visualization and Computer Graphics | Year: 2017

We propose a new shape analysis approach based on the non-local analysis of local shape variations. Our method relies on a novel description of shape variations, called Local Probing Field (LPF), which describes how a local probing operator transforms a pattern onto the shape. By carefully optimizing the position and orientation of each descriptor, we are able to capture shape similarities and gather them into a geometrically relevant dictionary over which the shape decomposes sparsely. This new representation permits to handle shapes with mixed intrinsic dimensionality (e.g. shapes containing both surfaces and curves) and to encode various shape features such as boundaries. Our shape representation has several potential applications; here we demonstrate its efficiency for shape resampling and point set denoising for both synthetic and real data. IEEE

Taffar M.,Jijel University | Miguet S.,CNRS Laboratory of Images and Information Systems Information Technology
Pattern Analysis and Applications | Year: 2017

In this work, we propose a new formulation of the objects modeling combining geometry and appearance; it is useful for detection and recognition. The object local appearance location is referenced with respect to an invariant which is a geometric landmark. The appearance (shape and texture) is a combination of Harris–Laplace descriptor and local binary pattern (LBP), all being described by the invariant local appearance model (ILAM). We use an improved variant of LBP traits at regions located by Harris–Laplace detector to encode local appearance. We applied the model to describe and learn object appearances (e.g., faces) and to recognize them. Given the extracted visual traits from a test image, ILAM model is carried out to predict the most similar features to the facial appearance: first, by estimating the highest facial probability and then in terms of LBP histogram-based measure, by computing the texture similarity. Finally, by a geometric calculation the invariant allows to locate an appearance in the image. We evaluate the model by testing it on different face images databases. The experiments show that the model results in high accuracy of detection and provides an acceptable tolerance to the appearance variability. © 2017 Springer-Verlag London Ltd.

Morel M.,CNRS Laboratory of Images and Information Systems Information Technology | Gesquiere G.,CNRS Laboratory of Images and Information Systems Information Technology
Eurographics Workshop on Urban Data Modelling and Visualisation, UDMV 2014 - Proceedings | Year: 2014

An increasing number of cities are developing digital models. It becomes thus necessary to take into account changes over time. Interoperability and thus the use of standards is also recommended. In this paper, we propose a new method, based on CityGML to take into account changes in the objects which compose the city. This method is efficient for any kind of changes of the city objects (semantic, geometry, topology or appearance). We then propose an extension of our method in order to consider more frequent changes as it is the case with sensors data that can be linked with part of city objects. © The Eurographics Association 2014.

Bulbul A.,Bilkent University | Capin T.,Bilkent University | Lavoue G.,INSA Lyon | Lavoue G.,CNRS Laboratory of Images and Information Systems Information Technology | Preda M.,Orange Group
IEEE Signal Processing Magazine | Year: 2011

Recent advances in evaluating and measuring the perceived visual quality of three-dimensional (3-D) polygonal models are presented in this article, which analyzes the general process of objective quality assessment metrics and subjective user evaluation methods and presents a taxonomy of existing solutions. Simple geometric error computed directly on the 3-D models does not necessarily reflect the perceived visual quality; therefore, integrating perceptual issues for 3-D quality assessment is of great significance. This article discusses existing metrics, including perceptually based ones, computed either on 3-D data or on two-dimensional (2-D) projections, and evaluates their performance for their correlation with existing subjective studies. © 2011 IEEE.

Andres E.,University of Poitiers | Roussillon T.,CNRS Laboratory of Images and Information Systems Information Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

In this paper we propose an analytical description of different kinds of digital circles that appear in the literature and especially in digital circle recognition algorithms. © 2011 Springer-Verlag.

Berry H.,French Institute for Research in Computer Science and Automation | Berry H.,CNRS Laboratory of Images and Information Systems Information Technology | Chate H.,CEA Saclay Nuclear Research Center
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014

In vivo measurements of the passive movements of biomolecules or vesicles in cells consistently report "anomalous diffusion," where mean-squared displacements scale as a power law of time with exponent α<1 (subdiffusion). While the detailed mechanisms causing such behaviors are not always elucidated, movement hindrance by obstacles is often invoked. However, our understanding of how hindered diffusion leads to subdiffusion is based on diffusion amidst randomly located immobile obstacles. Here, we have used Monte Carlo simulations to investigate transient subdiffusion due to mobile obstacles with various modes of mobility. Our simulations confirm that the anomalous regimes rapidly disappear when the obstacles move by Brownian motion. By contrast, mobile obstacles with more confined displacements, e.g., Orstein-Ulhenbeck motion, are shown to preserve subdiffusive regimes. The mean-squared displacement of tracked protein displays convincing power laws with anomalous exponent α that varies with the density of Orstein-Ulhenbeck (OU) obstacles or the relaxation time scale of the OU process. In particular, some of the values we observed are significantly below the universal value predicted for immobile obstacles in two dimensions. Therefore, our results show that subdiffusion due to mobile obstacles with OU type of motion may account for the large variation range exhibited by experimental measurements in living cells and may explain that some experimental estimates are below the universal value predicted for immobile obstacles. © 2014 American Physical Society.

Duchateau F.,CNRS Laboratory of Images and Information Systems Information Technology
DATA 2013 - Proceedings of the 2nd International Conference on Data Technologies and Applications | Year: 2013

The Web 2.0 and the inexpensive cost of storage have pushed towards an exponential growth in the volume of collected and produced data. However, the integration of distributed and heterogeneous data sources has become the bottleneck for many applications, and it therefore still largely relies on manual tasks. One of this task, named matching or alignment, is the discovery of correspondences, i.e., semantically-equivalent elements in different data sources. Most approaches which attempt to solve this challenge face the issue of deciding whether a pair of elements is a correspondence or not, given the similarity value(s) computed for this pair. In this paper, we propose a generic and flexible framework for selecting the correspondences by relying on the discriminative similarity values for a pair. Running experiments on a public dataset has demonstrated the im-provment in terms of quality and the robustness for adding new similarity measures without user intervention for tuning.

Mandin S.,CNRS Laboratory of Images and Information Systems Information Technology
Proceedings - IEEE 14th International Conference on Advanced Learning Technologies, ICALT 2014 | Year: 2014

Our aim is to improve the summary activity and the understanding of texts. We design a TEL environment, Resum'Web, which we present to grade 10 students. It delivers feedback, not necessarily correct, on two tasks: 1) selection of important sentences and 2) identification of type of produced sentences. The system appears to benefit the first task and the produced sentences distribution when the important sentences of a text are more salient. However, we do not observe any effect on the first task nor on the understanding. © 2014 IEEE.

Elghazel H.,CNRS Laboratory of Images and Information Systems Information Technology | Benabdeslem K.,CNRS Laboratory of Images and Information Systems Information Technology
Neural Processing Letters | Year: 2014

Self-organizing map (SOM) is an artificial neural network tool that is trained using unsupervised learning to produce a low dimensional representation of the input space, called a map. This map is generally the object of a clustering analysis step which aims to partition the referents vectors (map neurons) into compact and well-separated groups. In this paper, we consider the problem of the clustering SOM using different aspects: partitioning, hierarchical and graph coloring based techniques. Unlike the traditional clustering SOM techniques, which use k-means or hierarchical clustering, the graph-based approaches have the advantage of providing a partitioning of the SOM by simultaneously using dissimilarities and neighborhood relations provided by the map. We present the experimental results of several comparisons between these different ways of clustering. © 2013 Springer Science+Business Media New York.

Loading CNRS Laboratory of Images and Information Systems Information Technology collaborators
Loading CNRS Laboratory of Images and Information Systems Information Technology collaborators