LSTSQ: a module for reliable constrained and unconstrained nonlinear regression

A software module for nonlinear regression analysis, based on the reliable Meyer-Roth algorithm (a modified damped least square algorithm), is presented. It allows both constrained and unconstrained optimization, and the use of a variety of weighting methods. Virtually any nonlinear function can be fitted, including those with several nondependent variables. The package has been thoroughly tested, and is available in several common computer languages (Pascal, Modula-2 and C). It is easy to use, and advanced knowledge of mathematics or computers is not essential. Standard test problems, and a fully working example of use on enzyme kinetics are included.     

Multimodal biometric system for ECG,ear and iris recognition based on local descriptors

Multimedia Tools and Applications - Combination of multiple information extracted from different biometric modalities in multimodal biometric recognition system aims to solve the different...     

Face detection and recognition in an unconstrained environment for mobile visual assistive system

We present a visual assistive system that features mobile face detection and recognition in an unconstrained environment from a mobile source using convolutional neural networks. The goal of the system is to effectively detect individuals that approach facing towards the person equipped with the system. We find that face detection and recognition becomes a very difficult task due to the movement of the user which causes camera shakes resulting in motion blur and noise in the input for the visual assistive system. Due to the shortage of related datasets, we create a dataset of videos captured from a mobile source that features motion blur and noise from camera shakes. This makes the application a very challenging aspect of face detection and recognition in unconstrained environments. The performance of the convolutional neural network is further compared with a cascade classifier. The results show promising performance in daylight and artificial lighting conditions while the challenges lie for moonlight conditions with the need for reduction of false positives in order to develop a robust system. We also provide a framework for implementation of the system with smartphones and wearable devices for video input and auditory notification from the system to guide the visually impaired.     

Image warping for face recognition: From local optimality towards global optimization

This paper systematically analyzes the strengths and weaknesses of existing image warping algorithms on the tasks of face recognition. Image warping is used to cope with local and global image variability and in general is an NP-complete problem. Although many approximations have recently been proposed, neither thorough comparison, nor systematic analysis of methods in a common scheme has been done so far. We follow the bottom-up approach and analyze the methods with increasing degree of image structure preserved during optimization. We evaluate the presented warping approaches on four challenging face recognition tasks in highly variable domains. Our findings indicate that preserving maximum dependencies between neighboring pixels by imposing strong geometrical constraints leads to the best recognition results while making optimization efficient.     

From convex feasibility to convex constrained optimization using block action projection methods and underrelaxation

We describe the evolution of projection methods for solving convex feasibility problems to optimization methods when inconsistency arises, finally deriving from them, in a natural way, a general block method for convex constrained optimization. We present convergence results.     

Texture and shape information fusion for facial expression and facial action unit recognition

A novel method based on fusion of texture and shape information is proposed for facial expression and Facial Action Unit (FAU) recognition from video sequences. Regarding facial expression recognition, a subspace method based on Discriminant Non-negative Matrix Factorization (DNMF) is applied to the images, thus extracting the texture information. In order to extract the shape information, the system firstly extracts the deformed Candide facial grid that corresponds to the facial expression depicted in the video sequence. A Support Vector Machine (SVM) system designed on an Euclidean space, defined over a novel metric between grids, is used for the classification of the shape information. Regarding FAU recognition, the texture extraction method (DNMF) is applied on the differences images of the video sequence, calculated taking under consideration the neutral and the expressive frame. An SVM system is used for FAU classification from the shape information. This time, the shape information consists of the grid node coordinate displacements between the neutral and the expressed facial expression frame. The fusion of texture and shape information is performed using various approaches, among which are SVMs and Median Radial Basis Functions (MRBFs), in order to detect the facial expression and the set of present FAUs. The accuracy achieved using the Cohn–Kanade database is 92.3% when recognizing the seven basic facial expressions (anger, disgust, fear, happiness, sadness, surprise and neutral), and 92.1% when recognizing the 17 FAUs that are responsible for facial expression development.     

Deep learning network model based on fusion of spatiotemporal features for action recognition

Multimedia Tools and Applications - In view of the problem that the current deep learning network does not fully extract and fuse spatio-temporal information in the action recognition task,...     

Reorganizing local image features with chaotic maps: an application to texture recognition

Multimedia Tools and Applications - Texture images are those where the focus of the analysis is on the spatial arrangement of pixels (primitives or textons) rather than on particular objects in the...     

Recent evolution of modern datasets for human activity recognition: a deep survey

Multimedia Systems - Human activity recognition has been a significant goal of computer vision since its inception and has developed considerably in the last years. Recent approaches to this...     

On the choice of importance distributions for unconstrained and constrained state estimation using particle filter

Recursive state estimation of constrained nonlinear dynamical system has attracted the attention of many researchers in recent years. For nonlinear/non-Gaussian state estimation problems, particle filters have been widely used (Arulampalam et al. [1]). As pointed out by Daum [2], particle filters require a proposal distribution and the choice of proposal distribution is the key design issue. In this paper, a novel approach for generating the proposal distribution based on a constrained Extended Kalman filter (C-EKF), Constrained Unscented Kalman filter (C-UKF) and constrained Ensemble Kalman filter (C-EnkF) has been proposed. The efficacy of the proposed state estimation algorithms using a particle filter is illustrated via a successful implementation on a simulated gas-phase reactor, involving constraints on estimated state variables and another example problem, which involves constraints on the process noise (Rao et al. [10]). We also propose a state estimation scheme for estimating state variables in an autonomous hybrid system using particle filter with Unscented Kalman filter as a proposal and unconstrained Ensemble Kalman filter (EnKF) as a proposal. The efficacy of the proposed state estimation scheme for an autonomous hybrid system is demonstrated by conducting simulation studies on a three-tank hybrid system. The simulation studies underline the crucial role played by the choice of proposal distribution in formulation of particle filters.