nils-herrmann/clean_scirepeval huggingface dataset:
Mobile User Authentication Using Statistical Touch Dynamics Images

Behavioral biometrics have recently begun to gain attention for mobile user authentication. The feasibility of touch gestures as a novel modality for behavioral biometrics has been investigated. In this paper, we propose applying a statistical touch dynamics image (aka statistical feature model) trained from graphic touch gesture features to retain discriminative power for user authentication while significantly reducing computational time during online authentication. Systematic evaluation and comparisons with state-of-the-art methods have been performed on touch gesture data sets. Implemented as an Android App, the usability and effectiveness of the proposed method have also been evaluated.
Markov Random Field-based fitting of a subdivision-based geometric atlas

An accurate labeling of a multi-part, complex anatomical structure (e.g., brain) is required in order to compare data across images for spatial analysis. It can be achieved by fitting an object-specific geometric atlas that is constructed using a partitioned, high-resolution deformable mesh and tagging each of its polygons with a region label. Subdivision meshes have been used to construct such an atlas because they can provide a compact representation of a partitioned, multi-resolution, object-specific mesh structure using only a few control points. However, automated fitting of a subdivision mesh-based geometric atlas to an anatomical structure in an image is a difficult problem and has not been sufficiently addressed. In this paper, we propose a novel Markov Random Field-based method for fitting a planar, multi-part subdivision mesh to anatomical data. The optimal fitting of the atlas is obtained by determining the optimal locations of the control points. We also tackle the problem of landmark matching in tandem with atlas fitting by constructing a single graphical model to impose pose-invariant, landmark-based geometric constraints on atlas deformation. The atlas deformation is also governed by additional constraints imposed by the mesh's geometric properties and the object boundary. We demonstrate the potential of the proposed method on the difficult problem of segmenting a mouse brain and its interior regions in gene expression images which exhibit large intensity and shape variability. We obtain promising results when compared with manual annotations and prior methods.
8D-THERMO CAM: Combination of Geometry with Physiological Information for Face Recognition

Biometrics-based technologies in the area of identity management are gaining increasing importance, as a means of establishing non-falsifiable credentials for end users. However, in the three-way tug-of-war between convenient, unobtrusive data collection (required for user acceptance), accuracy in results (required for justifying deployment), and speed (required for widespread use in practice), no single biometric to date has managed to hold the middle ground that would allow for its ready adoption. The overall goal of our project is to develop the theoretical framework and computational tools that will lead to the development of a practical, unobtrusive, and accurate face recognition system for convenient and effective access control. This framework encompasses 8D characteristics of the face (3D geometry+2D visible texture+2D infrared texture, over time). In this paper, we present a novel multi-modal facial recognition approach that employs data from both visible spectrum and thermal infrared sensors. From the fitted parametric model we extract two images corresponding to the subject's face and process these images to extract biometric signatures. Specifically, the deformation image is compressed using a wavelet transform and the vasculature graph is extracted from the parametric thermal image.
Learning-Based Segmentation Framework for Tissue Images Containing Gene Expression Data

Associating specific gene activity with functional locations in the brain results in a greater understanding of the role of the gene. To perform such an association for the more than 20 000 genes in the mammalian genome, reliable automated methods that characterize the distribution of gene expression in relation to a standard anatomical model are required. In this paper, we propose a new automatic method that results in the segmentation of gene expression images into distinct anatomical regions in which the expression can be quantified and compared with other images. Our contribution is a novel hybrid atlas that utilizes a statistical shape model based on a subdivision mesh, texture differentiation at region boundaries, and features of anatomical landmarks to delineate boundaries of anatomical regions in gene expression images. This atlas, which provides a common coordinate system for internal brain data, is being used to create a searchable database of gene expression patterns in the adult mouse brain. Our framework annotates the images about four times faster and has achieved a median spatial overlap of up to 0.92 compared with expert segmentation in 64 images tested. This tool is intended to help scientists interpret large-scale gene expression patterns more efficiently
Wavelet-Based Bayesian Image Estimation: From Marginal and Bivariate Prior Models to Multivariate Prior Models

Prior models play an important role in the wavelet-based Bayesian image estimation problem. Although it is well known that a residual dependency structure always remains among natural image wavelet coefficients, only few multivariate prior models with a closed parametric form are available in the literature. In this paper, we develop new multivariate prior models that not only match well with the observed statistics of the wavelet coefficients of natural images, but also have a simple parametric form. These prior models are very effective for Bayesian image estimation and lead to an improved estimation performance over related earlier techniques.
3D Facial Landmark Detection under Large Yaw and Expression Variations

A 3D landmark detection method for 3D facial scans is presented and thoroughly evaluated. The main contribution of the presented method is the automatic and pose-invariant detection of landmarks on 3D facial scans under large yaw variations (that often result in missing facial data), and its robustness against large facial expressions. Three-dimensional information is exploited by using 3D local shape descriptors to extract candidate landmark points. The shape descriptors include the shape index, a continuous map of principal curvature values of a 3D object's surface, and spin images, local descriptors of the object's 3D point distribution. The candidate landmarks are identified and labeled by matching them with a Facial Landmark Model (FLM) of facial anatomical landmarks. The presented method is extensively evaluated against a variety of 3D facial databases and achieves state-of-the-art accuracy (4.5-6.3 mm mean landmark localization error), considerably outperforming previous methods, even when tested with the most challenging data.
On the improvement of anthropometry and pose estimation from a single uncalibrated image

We developed a technique that allows semiautomatic estimation of anthropometry and pose from a single image. However, estimation was limited to a class of images for which an adequate number of human body segments were almost parallel to the image plane. We present a generalization of that estimation algorithm that exploits pairwise geometric relationships of body segments to allow estimation from a broader class of images. In addition, we refine our search space by constructing a fully populated discrete hyper-ellipsoid of stick human body models (SMs) in order to capture the variance of the statistical anthropometric information. As a result, a better initial estimate can be computed by our algorithm and thus the number of iterations needed during minimization are reduced by tenfold. We present our results over a variety of images to demonstrate the broad coverage of our algorithm.
Quo vadis cardiovascular informatics?

In spite of the advancement and proliferation of cardiovascular imaging, the rate of deaths due to unpredicted heart attack remains high. Thus, it becomes imperative to develop novel computational tools to mine quantitative parameters from the imaging data for early detection of asymptomatic cardiovascular disease. Coronary calcification burden has been reported to be a significant and independent predictor of the atherosclerosis disease, and is associated with future cardiac events. Additionally, increased neovascularization of the plaque has been identified as a common feature of coronary plaque inflammation and has been defined as a plaque vulnerability index. In this paper, we present methods to extract and quantify coronary calcifications in the non-contrast cardiac CT scans and to detect neovascularization in the coronary vessels using contrast-enhanced intra-vascular ultrasound imaging.
Semi-coupled basis and distance metric learning for cross-domain matching: Application to low-resolution face recognition

In this paper, we propose a method for matching biometric data from disparate domains. Specifically, we focus on the problem of comparing a low-resolution (LR) image with a high-resolution (HR) one. Existing coupled mapping methods do not fully exploit the HR information or they do not simultaneously use samples from both domains during training. To this end, we propose a method that learns coupled distance metrics in two steps. In addition, we propose to jointly learn two semi-coupled bases that yield optimal representations. In particular, the HR images are used to learn a basis and a distance metric that result in increased class-separation. The LR images are then used to learn a basis and a distance metric that map the LR data to their class-discriminated HR pairs. Finally, the two distance metrics are refined to simultaneously enhance the class-separation of both HR class-discriminated and LR projected images. We illustrate that different distance metric learning approaches can be employed in conjunction with our framework. Experimental results on Multi-PIE and SCface, along with the relevant hypothesis tests, provide evidence of the effectiveness of the proposed approach.
Local classifier chains for deep face recognition

This paper focuses on improving the performance of current convolutional neural networks in face recognition without changing the network architecture. We propose a hierarchical framework that builds chains of local binary neural networks after one global neural network over all the class labels, Local Classifier Chains based Convolutional Neural Networks (LCC-CNN). Two different criteria based on a similarity matrix and confusion matrix are introduced to select binary label pairs to create local deep networks. To avoid error propagation, each testing sample travels through one global model and a local classifier chain to obtain its final prediction. The proposed framework has been evaluated with UHDB31 and CASIA-WebFace datasets. The experimental results indicate that our framework achieves better performance when compared with using only baseline methods as the global deep network. The accuracy is improved by 2.7% and 0.7% on the two datasets, respectively.
Evaluation of a 3D-aided pose invariant 2D face recognition system

A few well-developed face recognition pipelines have been reported in recent years. Most of the face-related work focuses on a specific module or demonstrates a research idea. In this paper, we present a pose-invariant 3D-aided 2D face recognition system (3D2D-PIFR) that is robust to pose variations as large as 90° by leveraging deep learning technology. We describe the architecture and the interface of 3D2D-PIFR, and introduce each module in detail. Experiments are conducted on the UHDB31 and IJB-A, demonstrating that 3D2D-PIFR outperforms existing 2D face recognition systems such as VGG-Face, FaceNet, and a commercial off-the-shelf software (COTS) by at least 9% on UHDB31 and 3% on IJB-A dataset on average. It fills a gap by providing a 3D-aided 2D face recognition system that has compatible results with 2D face recognition systems using deep learning techniques.
Automated Pericardial Fat Quantification in CT Data

Recent evidence indicates that pericardial fat may be a significant cardiovascular risk factor. Although pericardial fat is routinely imaged during computed tomography (CT) for coronary calcium scoring, it is currently ignored in the analysis of CT images. The primary reason for this is the absence of a tool capable of automatic quantification of pericardial fat. Recent studies on pericardial fat imaging were limited to manually outlined regions-of-interest and preset fat attenuation thresholds, which are subject to inter-observer and inter-scan variability. In this paper, we present a method for automatic pericardial fat burden quantification and classification. We evaluate the performance of our method using data from 23 subjects with very encouraging results
Inferring Human Activities Using Robust Privileged Probabilistic Learning

Classification models may often suffer from "structure imbalance" between training and testing data that may occur due to the deficient data collection process. This imbalance can be represented by the learning using privileged information (LUPI) paradigm. In this paper, we present a supervised probabilistic classification approach that integrates LUPI into a hidden conditional random field (HCRF) model. The proposed model is called LUPI-HCRF and is able to cope with additional information that is only available during training. Moreover, the proposed method employes Student's t-distribution to provide robustness to outliers by modeling the conditional distribution of the privileged information. Experimental results in three publicly available datasets demonstrate the effectiveness of the proposed approach and improve the state-of-the-art in the LUPI framework for recognizing human activities.
Benchmarking 3D Pose Estimation for Face Recognition

3D-Model-Aided 2D face recognition (MaFR) has attracted a lot of attention in recent years. By registering a 3D model, facial textures of the gallery and the probe can be lifted and aligned in a common space, thus alleviating the challenge of pose variations. One obstacle preventing accurate registration is the 3D-2D pose estimation, which is easily affected by landmarks. In this work, we present the performance that state-of-the-art pose estimation algorithms could reach using state-of-the-art automatic landmark localization methods. We generated an application-specific dataset with more than 59,000 synthetic face images and ground truth camera pose and landmarks, covering 45 poses and six illumination conditions. Our experiments compared four recently proposed pose estimation algorithms using 2D landmarks detected by two automatic methods. Our results highlight one near-real-time landmark detection method and a highly accurate pose estimation algorithm, which would potentially boost the 3D-Model-Aided 2D face recognition performance.
3D human body model acquisition from multiple views

We present a novel motion-based approach for the part determination and shape estimation of a human's body parts. The novelty of the technique is that neither a prior model of the human body is employed nor prior body part segmentation is assumed. We present a human body part identification strategy (HBPIS) that recovers all the body parts of a moving human based on the spatiotemporal analysis of its deforming silhouette. We formalize the process of simultaneous part determination and 2D shape estimation by employing the supervisory control theory of discrete event systems. In addition, in order to acquire the 3D shape of the body parts, we present a new algorithm which selectively integrates the (segmented by the HBPIS) apparent contours, from three mutually orthogonal views. The effectiveness of the approach is demonstrated through a series of experiments, where a subject performs a set of movements according to a protocol that reveals the structure of the human body.<<ETX>>
Can we do better in unimodal biometric systems? A novel rank-based score normalization framework for multi-sample galleries

The large amount of research on multimodal systems raises an important question: can we extract additional information from unimodal systems? In this paper, we propose a rank-based score normalization framework that addresses this problem when multi-sample galleries are avail-able. The main idea is to partition the matching scores into subsets and normalize each subset independently. In addition, we present two versions of our framework that: (i) use gallery-based information (i.e., gallery versus gallery scores), and (ii) update available information in an online fashion. We use the theory of Stochastic Dominance to illustrate that the proposed framework can increase the system's performance. Our approach: (i) does not require tuning of any parameters, (ii) can be used in conjunction with any score normalization technique and any integration rule, and (iii) extends the use of W-score normalization to multisample galleries. While our approach is better suited for an Open-set Identification task, we also demonstrate that it can be used for a Verification task. In order to assess the performance of the proposed framework we conduct experiments using the BDCP Face database. Our approach improves the Detection and Identification Rate by 14.87% for Z-score and by 4.82% for W-score.
Lossless 3-D reconstruction and registration of semi-quantitative gene expression data in the mouse brain

As imaging, computing, and data storage technologies improve, there is an increasing opportunity for multiscale analysis of three-dimensional datasets (3-D). Such analysis enables, for example, microscale elements of multiple macroscale specimens to be compared throughout the entire macroscale specimen. Spatial comparisons require bringing datasets into co-alignment. One approach for co-alignment involves elastic deformations of data in addition to rigid alignments. The elastic deformations distort space, and if not accounted for, can distort the information at the microscale. The algorithms developed in this work address this issue by allowing multiple data points to be encoded into a single image pixel, appropriately tracking each data point to ensure lossless data mapping during elastic spatial deformation. This approach was developed and implemented for both 2-D and 3D registration of images. Lossless reconstruction and registration was applied to semi-quantitative cellular gene expression data in the mouse brain, enabling comparison of multiple spatially registered 3-D datasets without any augmentation of the cellular data. Standard reconstruction and registration without the lossless approach resulted in errors in cellular quantities of ∼ 8%.
Bidirectional relighting for 3D-aided 2D face recognition

In this paper, we present a new method for bidirectional relighting for 3D-aided 2D face recognition under large pose and illumination changes. During subject enrollment, we build subject-specific 3D annotated models by using the subjects' raw 3D data and 2D texture. During authentication, the probe 2D images are projected onto a normalized image space using the subject-specific 3D model in the gallery. Then, a bidirectional relighting algorithm and two similarity metrics (a view-dependent complex wavelet structural similarity and a global similarity) are employed to compare the gallery and probe. We tested our algorithms on the UHDB11 and UHDB12 databases that contain 3D data with probe images under large lighting and pose variations. The experimental results show the robustness of our approach in recognizing faces in difficult situations.
PDM-ENLOR: Learning Ensemble of Local PDM-Based Regressions

Statistical shape models, such as Active Shape Models (ASMs), suffer from their inability to represent a large range of variations of a complex shape and to account for the large errors in detection of model points. We propose a novel method (dubbed PDM-ENLOR) that overcomes these limitations by locating each shape model point individually using an ensemble of local regression models and appearance cues from selected model points. Our method first detects a set of reference points which were selected based on their saliency during training. For each model point, an ensemble of regressors is built. From the locations of the detected reference points, each regressor infers a candidate location for that model point using local geometric constraints, encoded by a point distribution model (PDM). The final location of that point is determined as a weighted linear combination, whose coefficients are learnt from the training data, of candidates proposed from its ensemble's component regressors. We use different subsets of reference points as explanatory variables for the component regressors to provide varying degrees of locality for the models in each ensemble. This helps our ensemble model to capture a larger range of shape variations as compared to a single PDM. We demonstrate the advantages of our method on the challenging problem of segmenting gene expression images of mouse brain.
Active part-decomposition, shape and motion estimation of articulated objects: a physics-based approach

We present a novel, robust, integrated approach to segmentation shape and motion estimation of articulated objects. Initially, we assume the object consists of a single part, and we fit a deformable model to the given data using our physics-based framework. As the object attains new postures, we decide based on certain criteria if and when to replace the initial model with two new models. These criteria are based on the model's state and the given data. We then fit the models to the data using a novel algorithm for assigning forces from the data to the two models, which allows partial overlap between them and determination of joint location. This approach is applied iteratively until all the object's moving parts are identified. Furthermore, we define new global deformations and we demonstrate our technique in a series of experiments, where Kalman filtering is employed to account for noise and occlusion.<<ETX>>
Towards automatic reconstruction of dendrite morphology from live neurons

The recent advent of optical imaging methods to capture both structural and functional data from living neurons holds the promise of improving our understanding of neuronal function. An important technical advance would be to use computer simulations to determine the optimal locations for high-speed functional imaging and electrical recording on an individual neuron. However, such simulations require a precise reconstruction of the dendritic morphology. Thus, the currently available time-consuming, semi-manual methods for morphological reconstruction prevent integration of cell-specific simulations into the experiments. Our work focuses on implementing a fast, robust method for extracting dendrite morphology from confocal or two-photon images to enable concurrent simulation and functional imaging of individual neurons. We discuss the current implementation of the morphological reconstruction, our approach to validation, and our initial results.