Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743778
A. Bevilacqua, A. Gherardi, L. Carozza
Many methods are known in literature to reconstruct the camera response function (RF), whether they use calibration chart or images of arbitrary scenes taken at different exposures. This works in case to have at one's disposal a camera with enough exposure steps to capture the whole dynamic range of the scene, representatively. However, in case of entry-level or low quality cameras, the resolution in the shutter time range of variation could yield just a reduced set of samples. Here we propose additional constraints to a well known method to reconstruct a RF even in the case that just a reduced set of exposures is available. Extensive experiments carried out using both a low quality and a professional camera commonly used in computer vision applications show the improvement achieved by our method in the reconstructed RF in case of few samples.
{"title":"A robust approach to reconstruct experimentally the camera response function","authors":"A. Bevilacqua, A. Gherardi, L. Carozza","doi":"10.1109/IPTA.2008.4743778","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743778","url":null,"abstract":"Many methods are known in literature to reconstruct the camera response function (RF), whether they use calibration chart or images of arbitrary scenes taken at different exposures. This works in case to have at one's disposal a camera with enough exposure steps to capture the whole dynamic range of the scene, representatively. However, in case of entry-level or low quality cameras, the resolution in the shutter time range of variation could yield just a reduced set of samples. Here we propose additional constraints to a well known method to reconstruct a RF even in the case that just a reduced set of exposures is available. Extensive experiments carried out using both a low quality and a professional camera commonly used in computer vision applications show the improvement achieved by our method in the reconstructed RF in case of few samples.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133803352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743781
Z. Haddad, Azeddine Beghdadi, A. Serir, A. Mokraoui
In this paper, a new method for fingerprint identification based on Radon transform is proposed as an alternative to minutiae-based approaches. Since existing methods based on these local characteristics "minutiae" have attained a level of success rate saturation, this paper aims to open a new gateway by proposing a different approach for analyzing fingerprints. This approach offers a fine analysis from global characteristics via the generated Radon profiles. The basic idea is to exploit the directional properties of Radon transform in order to extract new global features from fingerprint images, which could be considered as a set of oriented patterns. A global structural similarity based on these directional features is then derived. This new approach does not necessitate any pre-processing and treatments as in classical fingerprint identification methods. To evaluate the performance of the proposed method, some fingerprints images are used. The obtained results confirm the efficiency of the method in terms of flexibility, simplicity and quality of identification.
{"title":"Fingerprint Identification using Radon Transform","authors":"Z. Haddad, Azeddine Beghdadi, A. Serir, A. Mokraoui","doi":"10.1109/IPTA.2008.4743781","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743781","url":null,"abstract":"In this paper, a new method for fingerprint identification based on Radon transform is proposed as an alternative to minutiae-based approaches. Since existing methods based on these local characteristics \"minutiae\" have attained a level of success rate saturation, this paper aims to open a new gateway by proposing a different approach for analyzing fingerprints. This approach offers a fine analysis from global characteristics via the generated Radon profiles. The basic idea is to exploit the directional properties of Radon transform in order to extract new global features from fingerprint images, which could be considered as a set of oriented patterns. A global structural similarity based on these directional features is then derived. This new approach does not necessitate any pre-processing and treatments as in classical fingerprint identification methods. To evaluate the performance of the proposed method, some fingerprints images are used. The obtained results confirm the efficiency of the method in terms of flexibility, simplicity and quality of identification.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132925089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743801
Mohamed Deriche
Several systems require authenticating a person's identity before giving access to resources. Biometrics has long been known as a robust approach for person authentication. However, most monomodal biometrics are proven to exhibit one or more weaknesses. In this respect, evidence reconciliation from different biometric systems (referred to as multibiometrics) has attracted much attention lately. Multibiometric systems combine the information presented by multiple biometric sensors, algorithms, samples, units, or traits. In addition to improving recognition accuracy, these systems are expected to improve population coverage, reduce spoofing and be resilient to fault tolerance of different monomodal biometric systems. Here, we present an overview of the different biometric systems, enumerate the advantages and weaknesses of such systems, and some of the newly introduced biometrics. We then discuss the various sources of biometric information that can be combined as well as the different levels of fusion in a multibiometric system. It is becoming increasingly evident that multibiometric systems will be the technology for person identification in the 21st century.
{"title":"Trends and Challenges in Mono and Multi Biometrics","authors":"Mohamed Deriche","doi":"10.1109/IPTA.2008.4743801","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743801","url":null,"abstract":"Several systems require authenticating a person's identity before giving access to resources. Biometrics has long been known as a robust approach for person authentication. However, most monomodal biometrics are proven to exhibit one or more weaknesses. In this respect, evidence reconciliation from different biometric systems (referred to as multibiometrics) has attracted much attention lately. Multibiometric systems combine the information presented by multiple biometric sensors, algorithms, samples, units, or traits. In addition to improving recognition accuracy, these systems are expected to improve population coverage, reduce spoofing and be resilient to fault tolerance of different monomodal biometric systems. Here, we present an overview of the different biometric systems, enumerate the advantages and weaknesses of such systems, and some of the newly introduced biometrics. We then discuss the various sources of biometric information that can be combined as well as the different levels of fusion in a multibiometric system. It is becoming increasingly evident that multibiometric systems will be the technology for person identification in the 21st century.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131343507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743734
M. Essabbah, J. Hérisson, S. Otmane, M. Mallem
It has been proven that three-dimensional architecture of DNA could bring more information to the molecule's analysis. However, genome's 3D representation has often been based on "naked" DNA. Thus, the techniques used have changed the molecule's nature making the 3D model less credible. However, further researches on chromosomes' organization have identified some data and models representing a part of this organization. The challenge is to synthesize what has been established in the literature. The molecule will be represented at the chromatin fiber level by means of 3D modeling algorithms. Initially, we have identified the biophysical data to be exploited. Indeed, we will first rely on the biophysical data of the chromatin's structure as the persistence length along with the diameter, the confined volume and the curvature energy in order to build a first simple model of the chromatin. This 3D model will be improved, as we will apply on it biological models.
{"title":"Towards a biophysical 3D model of the DNA","authors":"M. Essabbah, J. Hérisson, S. Otmane, M. Mallem","doi":"10.1109/IPTA.2008.4743734","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743734","url":null,"abstract":"It has been proven that three-dimensional architecture of DNA could bring more information to the molecule's analysis. However, genome's 3D representation has often been based on \"naked\" DNA. Thus, the techniques used have changed the molecule's nature making the 3D model less credible. However, further researches on chromosomes' organization have identified some data and models representing a part of this organization. The challenge is to synthesize what has been established in the literature. The molecule will be represented at the chromatin fiber level by means of 3D modeling algorithms. Initially, we have identified the biophysical data to be exploited. Indeed, we will first rely on the biophysical data of the chromatin's structure as the persistence length along with the diameter, the confined volume and the curvature energy in order to build a first simple model of the chromatin. This 3D model will be improved, as we will apply on it biological models.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122432257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743769
G. Laureano, M. D. de Paiva
Inspired by human vision system, the stereo vision is a very important area in computer vision. It is related with the 3D information recovery from a pair of images. Although it has being studied for quite a long time, the stereo vision presents some difficult problems, related to the change of visualization perspective. Among the different problems originated from point of view changes, occlusions and ambiguities have special attention and compose the foundation of stereo problem, named correspondence problem. In the related works, the local techniques are fast, but produce poor results whilst the global techniques produce good results but are very computationally expensive. This work aims to give a contribution to the correspondence problem in stereo matching using a local approach with two strategies as solution to ambiguities and occlusions: the multiresolution analysis with images pyramids and the perceptual grouping weight, called Gestalt Theory in the psychology. The obtained results were closer to the ones generated by global techniques, with the advantage of requiring less computational complexity. The use of Gestalt Theory makes this a modern disparity estimation method, due to this theory has received special attention in computer vision researches.
{"title":"Disparities Maps Generation Employing Multi-resolution Analysis and Perceptual Grouping","authors":"G. Laureano, M. D. de Paiva","doi":"10.1109/IPTA.2008.4743769","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743769","url":null,"abstract":"Inspired by human vision system, the stereo vision is a very important area in computer vision. It is related with the 3D information recovery from a pair of images. Although it has being studied for quite a long time, the stereo vision presents some difficult problems, related to the change of visualization perspective. Among the different problems originated from point of view changes, occlusions and ambiguities have special attention and compose the foundation of stereo problem, named correspondence problem. In the related works, the local techniques are fast, but produce poor results whilst the global techniques produce good results but are very computationally expensive. This work aims to give a contribution to the correspondence problem in stereo matching using a local approach with two strategies as solution to ambiguities and occlusions: the multiresolution analysis with images pyramids and the perceptual grouping weight, called Gestalt Theory in the psychology. The obtained results were closer to the ones generated by global techniques, with the advantage of requiring less computational complexity. The use of Gestalt Theory makes this a modern disparity estimation method, due to this theory has received special attention in computer vision researches.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121979228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743767
M. Ammar, S. Le Hégarat-Mascle, R. Reynaud, A. Robin
This paper aims at showing the interest of the a contrario framework for object detection in video scenes. In the two approaches presented here, objects are detected at a window level, considering all the pixels included in a given window to decide the presence or the absence of objects in the window. Now, according to the a contrario principle, windows with objects are detected as too exceptional realizations of the model representing the windows without objects. The interest of this latter model, called `naive' model, is that it is generally much simpler than the one representing the variety of objects. Two window-based algorithms are proposed, one using the fact that an appearing object can be characterized by significantly high values in the image representing the difference with a background or reference, and the other one using the fact that objects form clusters of object-labeled pixels. The performance of our approach (two algorithms) has been tested on video scenes respectively acquired outdoors and indoors. Both algorithms have also been compared to alternative detection methods, and they proved their performance Finally, the obtained results on artificial noised images show the high robustness relatively to noise of the proposed two-step detection method.
{"title":"Video Scene Object Detection Using An A Contrario Approach","authors":"M. Ammar, S. Le Hégarat-Mascle, R. Reynaud, A. Robin","doi":"10.1109/IPTA.2008.4743767","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743767","url":null,"abstract":"This paper aims at showing the interest of the a contrario framework for object detection in video scenes. In the two approaches presented here, objects are detected at a window level, considering all the pixels included in a given window to decide the presence or the absence of objects in the window. Now, according to the a contrario principle, windows with objects are detected as too exceptional realizations of the model representing the windows without objects. The interest of this latter model, called `naive' model, is that it is generally much simpler than the one representing the variety of objects. Two window-based algorithms are proposed, one using the fact that an appearing object can be characterized by significantly high values in the image representing the difference with a background or reference, and the other one using the fact that objects form clusters of object-labeled pixels. The performance of our approach (two algorithms) has been tested on video scenes respectively acquired outdoors and indoors. Both algorithms have also been compared to alternative detection methods, and they proved their performance Finally, the obtained results on artificial noised images show the high robustness relatively to noise of the proposed two-step detection method.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130215287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743747
N. Mezghani, A. Mitiche
Recent studies have shown that the Gibbs density function can model complex patterns and that a constrained maximum entropy formulation affords a powerful means of estimating its parameters from pattern class data. The theory, developed in the context of learning a prior model of natural images, has been applied successfully to the synthesis of textures and shapes, and to pattern classification. The basic parameter estimation algorithm rests on gradient algorithm following the maximization under constraints of an entropy criterion. The purpose of this study is to investigate a Gibbsian Kohonen neural network, a Kohonen network which can learn these constrained maximum entropy Gibbs density parameters for pattern representation and classification. Experiments in classification of handwritten characters verify the validity and efficiency of the method.
{"title":"Pattern classification by a Gibbsian Kohonen neural network with an application to Arabic character recognition","authors":"N. Mezghani, A. Mitiche","doi":"10.1109/IPTA.2008.4743747","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743747","url":null,"abstract":"Recent studies have shown that the Gibbs density function can model complex patterns and that a constrained maximum entropy formulation affords a powerful means of estimating its parameters from pattern class data. The theory, developed in the context of learning a prior model of natural images, has been applied successfully to the synthesis of textures and shapes, and to pattern classification. The basic parameter estimation algorithm rests on gradient algorithm following the maximization under constraints of an entropy criterion. The purpose of this study is to investigate a Gibbsian Kohonen neural network, a Kohonen network which can learn these constrained maximum entropy Gibbs density parameters for pattern representation and classification. Experiments in classification of handwritten characters verify the validity and efficiency of the method.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121056331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743796
F. Matta, J. Dugelay
In this article we present two physiological and behavioural approaches for person recognition using videos. The first system, called the multimodal recognition system, is divided in two modules. The first module exploits the behavioural information: it is based on statistical features computed using the displacement signals of the head; the second one is dealing with the physiological information: it is a probabilistic extension of the classic Eigenface approach. For a consistent fusion, both systems share the same probabilistic classification framework: a Gaussian Mixture Model (GMM) approximation and a Bayesian classifier. The second system, called the tomoface recognition system, applies discrete video tomography to compute spatiotemporal features that summarise the head and facial dynamics of a sequence into a single image (called "video X-ray image"); these novel features are subsequently analysed by an extended version of the eigenface approach. Finally, we assess the performances of both systems, and we compare them with a traditional recognition approach based on facial appearance.
{"title":"Physiological and behavioural approaches for person recognition using videos","authors":"F. Matta, J. Dugelay","doi":"10.1109/IPTA.2008.4743796","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743796","url":null,"abstract":"In this article we present two physiological and behavioural approaches for person recognition using videos. The first system, called the multimodal recognition system, is divided in two modules. The first module exploits the behavioural information: it is based on statistical features computed using the displacement signals of the head; the second one is dealing with the physiological information: it is a probabilistic extension of the classic Eigenface approach. For a consistent fusion, both systems share the same probabilistic classification framework: a Gaussian Mixture Model (GMM) approximation and a Bayesian classifier. The second system, called the tomoface recognition system, applies discrete video tomography to compute spatiotemporal features that summarise the head and facial dynamics of a sequence into a single image (called \"video X-ray image\"); these novel features are subsequently analysed by an extended version of the eigenface approach. Finally, we assess the performances of both systems, and we compare them with a traditional recognition approach based on facial appearance.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"os-42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127781004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-01DOI: 10.1109/IPTA.2008.4743750
M. Akhloufi, L. Rossi, L. Abdelhadi, Y. Tison
This work presents a new framework for three-dimensional reconstruction of dynamic fire fronts found in outdoor unstructured scenes. The proposed approach addresses the problem of segmenting fire front regions using color attributes and clustering techniques in order to extract salient points from stereo images. These points are then used to reconstruct their 3D position in the scene. A matching strategy is proposed to deal with mismatches due to occlusions and missing data. The proposed framework was successfully used to build 3D data part of dynamic fire fronts. This 3D information was used efficiently to estimate the approximate position of the fire front and its heading direction. The obtained results are promising and show the possibility of tracking dynamic objects with changing shapes like fire fronts in a three-dimensional space.
{"title":"Dynamic fire modeling in Three-dimensional space","authors":"M. Akhloufi, L. Rossi, L. Abdelhadi, Y. Tison","doi":"10.1109/IPTA.2008.4743750","DOIUrl":"https://doi.org/10.1109/IPTA.2008.4743750","url":null,"abstract":"This work presents a new framework for three-dimensional reconstruction of dynamic fire fronts found in outdoor unstructured scenes. The proposed approach addresses the problem of segmenting fire front regions using color attributes and clustering techniques in order to extract salient points from stereo images. These points are then used to reconstruct their 3D position in the scene. A matching strategy is proposed to deal with mismatches due to occlusions and missing data. The proposed framework was successfully used to build 3D data part of dynamic fire fronts. This 3D information was used efficiently to estimate the approximate position of the fire front and its heading direction. The obtained results are promising and show the possibility of tracking dynamic objects with changing shapes like fire fronts in a three-dimensional space.","PeriodicalId":384072,"journal":{"name":"2008 First Workshops on Image Processing Theory, Tools and Applications","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116754666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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