Papers by Samy Ait-aoudia
Lecture Notes in Computer Science, 2015
Medical imaging applications produce large sets of similar images. The huge amount of data makes ... more Medical imaging applications produce large sets of similar images. The huge amount of data makes the manual analysis and interpretation a fastidious task. Medical image segmentation is thus an important process in image processing used to partition the images into different regions (e.g. gray matter(GM), white matter(WM) and cerebrospinal fluid(CSF)). Hidden Markov Random Field (HMRF) Model and Gibbs distributions provide powerful tools for image modeling. In this paper, we use a HMRF model to perform segmentation of volumetric medical images. We have a problem with incomplete data. We seek the segmented images according to the MAP (Maximum A Posteriori) criterion. MAP estimation leads to the minimization of an energy function. This problem is computationally intractable. Therefore, optimizations techniques are used to compute a solution. We will evaluate the segmentation upon two major factors: the time of calculation and the quality of segmentation. Processing time is reduced by distributing the computation of segmentation on a powerful and inexpensive architecture that consists of a cluster of personal computers. Parallel programming was done by using the standard MPI (Message Passing Interface).
2011 15th International Conference on Information Visualisation, 2011
... Samy Ait-Aoudia, Ramdane Mahiou, Elhachemi Guerrout ESI - Ecole nationale Supérieure en Infor... more ... Samy Ait-Aoudia, Ramdane Mahiou, Elhachemi Guerrout ESI - Ecole nationale Supérieure en Informatique, BP 68M, O-Smar 16270 Algiers, Algeria [email protected], [email protected], [email protected] ... Potts model The Potts model is a generalization of the Ising model. ...
2010 20th International Conference on Pattern Recognition, 2010
The storage of fingerprints is an important issue as this biometric modality is more and more dep... more The storage of fingerprints is an important issue as this biometric modality is more and more deployed for real applications. The a prori impossibility to revoke a biometric template (like a password) in case of theft, is a major concern for privacy reasons. We propose in this paper a new method to secure fingerprint minutiae templates by storing a biocode while keeping good recognition results. We show the efficiency of the method in comparison to some published methods for different scenarios.
Proceedings Fifth International Conference on Information Visualisation, 2001
In computer aided design, geometric modelling by constraints enables users to describe geometric ... more In computer aided design, geometric modelling by constraints enables users to describe geometric objects by geometric constraints. Many resolution methods have been proposed for solving systems of geometric constraints. Geometric methods can be very efficient but are only applicable to particular kinds of problems (typically ruler and c0mpas.r constructive problems). Numerical methods can deal with all types of constraints but are time consuming. We present a hybrid method to solve the geometric constrainls by combining geometric solving with numerical meth0d.y. We "benefit" then of ihe .advantages of the two methods.
2010 14th International Conference Information Visualisation, 2010
Vision is central in human perception. Images are everywhere. Real life applications produce and ... more Vision is central in human perception. Images are everywhere. Real life applications produce and use huge amounts of different types images.
2008 3rd International Symposium on Communications, Control and Signal Processing, 2008
Registration is an important task in image processing used to match two or more images. In the fi... more Registration is an important task in image processing used to match two or more images. In the field of medical imaging, registration is used to match anatomic structures from two or more images taken at different times to track for example the evolution of a disease. Intensity based techniques are widely used in multimodal registration. To have the best matching, a cost function expressing the similarity between these images is maximized. To resolve this problem, we evaluate two global optimization techniques that are genetic algorithms and simulated annealing. In this paper we show some results obtained in medical images registration.
Geometric Modeling and Imaging (GMAI '07), 2007
Registration techniques in medical image processing are used to match anatomic structures from tw... more Registration techniques in medical image processing are used to match anatomic structures from two or more images (CT, MRI, PET,…) taken at different times to track for example the evolution of a disease. The core of the registration process is the maximization of a cost function expressing the similarity between these images. To resolve this problem, we have tested two global optimization techniques that are genetic algorithms and simulated annealing. In this paper we show some results obtained in medical images registration.
IEEE International Symposium on Signal Processing and Information Technology, 2013
ABSTRACT The image annotation is an effective technology for improving the Web image retrieval. M... more ABSTRACT The image annotation is an effective technology for improving the Web image retrieval. Many works have been proposed to increase the image auto-annotation performance. The annotation quality depends on many factors: segmentation, choice of visual features...etc.. An image contains several visuals information (color, texture, shape....) but the best choice of these parameters is a difficult problem. The main focus of this paper is two-fold. First, we compare between image annotations in latent space and textual space. Second, we survey influence of visual features choice on image annotation. For that, we developed two image auto-annotation systems (AIA-LSA, AIA-WLSA). For each one, we propose three prototypes based on different visual descriptors; such as: texture, color and fusion of both parameters. Corel data set is used to experiment our prototypes, the results show that the annotation by latent space is more efficient than the annotation by textual space and the best choice of visual features is a persistent problem in general images.
Journal of Computer Science, 2009
ABSTRACT Problem statement: The objective of this study particularly aims the static segmentation... more ABSTRACT Problem statement: The objective of this study particularly aims the static segmentation of the lips. Approach: For that, we proposed algorithms for the determination of certain characteristic points of the lips, as well as a method of optimal slope allowing to trace the cubic ones forming external contours of the lips. Results: Finally to make sure of the performance of our algorithms, we also used a manual determination of the characteristic points. Conclusion: The results obtained showed the rigor of our algorithms and that by comparing the results obtained by the manual determination with those of the semi-automatic determination.
Lecture Notes in Computer Science, 2006
Medical imaging applications produce large sets of similar images. Thus a compression technique i... more Medical imaging applications produce large sets of similar images. Thus a compression technique is useful to reduce space storage. Lossless compression methods are necessary in such critical applications. Volumetric medical data presents strong similarity between successive frames. In this paper we investigate predictive techniques for lossless compression of video sequences applied to volumetric data. We also make a comparative study with other existing compression techniques dedicated to volumetric data.
Lecture Notes in Computer Science, 2013
International Journal of Computational Vision and Robotics, 2011
MPEG4 is an ISO/IEC standard developed by moving picture experts group (MPEG). The standard video... more MPEG4 is an ISO/IEC standard developed by moving picture experts group (MPEG). The standard video MPEG-4 visual (part 2) introduces the notion of video objects (VO). Basically, the concept of the MPEG-4 compression relies on contents. On the other hand, the standard MPEG-4 AVC/H.264 (part 10) relies on the same architecture used in MPEG-2, which does not introduce the concept of video objects. The performances of these video coders depend mainly on motion estimation.
EURASIP Journal on Advances in Signal Processing, 2006
Medical imaging applications produce large sets of similar images. Thus a compression technique i... more Medical imaging applications produce large sets of similar images. Thus a compression technique is necessary to reduce space storage. Lossless compression methods are necessary in such critical applications. Set redundancy compression (SRC) methods exploit the interimage redundancy and achieve better results than individual image compression techniques when applied to sets of similar images. In this paper, we make a comparative study of SRC methods on sample datasets using various archivers. We also propose a new SRC method and compare it to existing SRC techniques.
Computers & Security, 2013
Cancelable template Smartcard a b s t r a c t We address in this paper the problem of privacy in ... more Cancelable template Smartcard a b s t r a c t We address in this paper the problem of privacy in fingerprint biometric systems. Today, cancelable techniques have been proposed to deal with this issue. Ideally, such transforms are one-way. However, even if they are with provable security, they remain vulnerable when the user-specific key that achieves cancelability property is stolen. The prominence of the cancelable template confidentiality to maintain the irreversibility property was also demonstrated for many proposed constructions. To prevent possible coming attacks, it becomes important to securely manage this key as well as the transformed template in order to avoid them being leaked simultaneously and thus compromised. To better manage the user credentials of cancelable constructs, we propose a new solution combining a trusted architecture and a cancelable fingerprint template. Therefore, a Bio-Hashed minutiae template based on a chip matching algorithm is proposed. A pkcs15 compliant cancelable biometric system for fingerprint privacy preserving is implemented on a smartcard. This closed system satisfies the safe management of the sensitive templates.
Uploads
Papers by Samy Ait-aoudia