206841351
Shape Normalisaiton for Face Recognition
This paper presents methods for shape normalisation of face images. Localisation and shape normalisation are prerequisites for face recognition algorithms like the eigenface approach. Other established face recognition methods like labeled graph matching can also be accelerated by providing normalised face image databases.
2648328
Face Authentication Using Morphological Dynamic Link Architecture
A very attractive approach for face detection is based on multiresolution images (also known as mosaic images). Motivated by the simplicity of this approach, a rule-based face detection algorithm in frontal views is developed first. Second, a novel dynamic link architecture based on multiscale morphological dilation-erosion is proposed for face authentication. More specifically, a sparse grid is placed over the outcome of face detection stage for each person in a reference set. Subsequently, multiscale morphological operations are employed to yield a feature vector at each node of the grid and dynamic link matching is applied to verify the identity of each person from a test set. The first experimental results reported in this paper verify the superiority of the proposed method over the (standard) dynamic link matching that is based on Gabor wavelets.
5805407
Expert Conciliation for Multi Modal Person Authentication Systems by Bayesian Statistics
We present an algorithm functioning as a supervisor module in a multi expert decision making machine. It uses the Bayes theory in order to estimate the biases of individual expert opinions. These are then used to calibrate and conciliate expert opinions to one opinion. We present a framework for simulating decision strategies using expert opinions whose properties are easily modifiable. By using real data coming from a person authentication system using image and speech data we were able to confirm that the proposed supervisor improves the quality of individual expert decisions by reaching success rates of 99.5 %.
3727579
Face authentication with Gabor information on deformable graphs
Elastic graph matching has been proposed as a practical implementation of dynamic link matching, which is a neural network with dynamically evolving links between a reference model and an input image. Each node of the graph contains features that characterize the neighborhood of its location in the image. The elastic graph matching usually consists of two consecutive steps, namely a matching with a rigid grid, followed by a deformation of the grid, which is actually the elastic part. The deformation step is introduced in order to allow for some deformation, rotation, and scaling of the object to be matched. This method is applied here to the authentication of human faces where candidates claim an identity that is to be checked. The matching error as originally suggested is not powerful enough to provide satisfying results in this case. We introduce an automatic weighting of the nodes according to their significance. We also explore the significance of the elastic deformation for an application of face-based person authentication. We compare performance results obtained with and without the second matching step. Results show that the deformation step slightly increases the performance, but has lower influence than the weighting of the nodes. The best results are obtained with the combination of both aspects. The results provided by the proposed method compare favorably with two methods that require a prior geometric face normalization, namely the synergetic and eigenface approaches.
23498103
Person Authentication by Fusing Face and Speech Information
Keywords: vision Reference EPFL-CONF-82406 Record created on 2006-03-10, modified on 2017-05-10
39157407
Automatic Identification of Diatoms Using Decision Forests
A feature based identification scheme for microscopic images of diatoms is presented in this paper. Diatoms are unicellular algae found in water and other places wherever there is humidity and enough light for photo synthesis. The proposed automatic identification scheme follows a decision tree based classification approach. In this paper two different ensemble learning methods are evaluated and results are compared with those of single decision trees. As test sets two different diatom image databases are used. For each image in the databases general features like symmetry, geometric properties, moment invariants, and Fourier descriptors as well as diatom specific features like striae density and direction are computed.
46027337
Identification of Diatoms by Grid Graph Matching
Diatoms are unicellular algae found in water and other places wherever there is humidity and enough light for photo synthesis. In this paper a graph matching based identification approach for the retrieval of diatoms from an image database is presented. The retrieval is based on the matching of labeled grid graphs carrying texture information of the underlying diatom. A grid graph is a regular, rectangular arrangement of nodes overlaid on an image. Each node of the graph is labeled with texture features describing a rectangular sub-region of the object. Properties of gray level co-occurrence matrices as well as of Gabor wavelets are used as texture features. The method has been evaluated on a diatom database holding images of 188 different diatoms belonging to 38 classes. For the identification of these diatoms recognition rates of more than 90 percent were obtained.
10391306
New Features of Latin Dances: Analysis of Salsa, ChaCha, and Rumba
The stream cipher Salsa20 was introduced by Bernstein in 2005 as a candidate in the eSTREAM project, accompanied by the reduced versions Salsa20/8 and Salsa20/12. ChaCha is a variant of Salsa20 aiming at bringing better diffusion for similar performance. Variants of Salsa20 with up to 7 rounds (instead of 20) have been broken by differential cryptanalysis, while ChaCha has not been analyzed yet. We introduce a novel method for differential cryptanalysis of Salsa20 and ChaCha, inspired by correlation attacks and related to the notion of neutral bits. This is the first application of neutral bits in stream cipher cryptanalysis. It allows us to break the 256-bit version of Salsa20/8, to bring faster attacks on the 7-round variant, and to break 6- and 7-round ChaCha. In a second part, we analyze the compression function Rumba, built as the XOR of four Salsa20 instances and returning a 512-bit output. We find collision and preimage attacks for two simplified variants, then we discuss differential attacks on the original version, and exploit a high-probability differential to reduce complexity of collision search from 2256to 279for 3-round Rumba. To prove the correctness of our approach we provide examples of collisions and near-collisions on simplified versions.
2647352
Experiences with an Emotional Sales Agent
With COSIMAB2B we demonstrate a prototype of a complex and visionary e-procurement application. The embodied character agent named COSIMA is able to respect a customer’s preferences and deals with him or her via natural speech. She expresses various emotions via mimic, gesture, combined with speech synthesis, and COSIMA is even able to consider the customer’s emotions via mimic recognition. As first observations show, this is a very promising approach to improve the bargaining with the customer or the recommendation of products.
3173103
Can the calculation of ligand binding free energies be improved with continuum solvent electrostatics and an ideal-gas entropy correction?
The prediction of a ligand binding constant requires generating three-dimensional structures of the complex concerned and reliably scoring these structures. Here, the scoring problem is investigated by examining benzamidine-like inhibitors of trypsin, a system for which errors in the structures are small. Precise and consistent binding free energies for the inhibitors are determined experimentally for this test system. To examine possible improvement of scoring methods, we test the suitability of continuum electrostatics to account for solvation effects and use an ideal-gas entropy correction to account for the changes in the degrees of freedom of the ligand. The small observed root-mean-square deviation of 0.55 kcal/mol of the calculated relative to the experimental values indicates that the essentials of the binding process have been captured. Even though all six ligands make the same salt bridge and H-bonds to the protein, the electrostatic contribution varies among the ligands by as much as 2 kcal/mol. Moreover, although the ligands are rigid and similar in size, the entropic terms also significantly affect the relative binding affinities (by up to 2.7 kcal/mol). The present approach to solvation and entropy may allow the ranking of the ligands to be considerably improved at a cost that makes the method applicable to the optimization of lead compounds or to the screening of small collections of ligands.