Frerk Saxen

• M.Eng.
• PhD Student at Otto-von-Guericke University Magdeburg

This study focuses on improving healthcare quality by introducing an automated system that continuously monitors patient pain intensity. The system analyzes the Electrodermal Activity (EDA) sensor modality modality, compares the results obtained from both EDA and facial expressions modalities, and late fuses EDA and facial expressions modalities. T...

Pain is a reliable indicator of health issues; it affects patients’ quality of life when not well managed. The current methods in the clinical application undergo biases and errors; moreover, such methods do not facilitate continuous pain monitoring. For this purpose, the recent methodologies in automatic pain assessment were introduced, which demo...

Automatic systems enable continuous monitoring of patients' pain intensity as shown in prior studies. Facial expression and physiological data such as electrodermal activity (EDA) are very informative for pain recognition. The features extracted from EDA indicate the stress and anxiety caused by different levels of pain. In this paper, we investiga...

Prior work on automated methods demonstrated that it is possible to recognize pain intensity from frontal faces in videos, while there is an assumption that humans are very adept at this task compared to machines. In this paper, we investigate whether such an assumption is correct by comparing the results achieved by two human observers with the re...

We address the problem of facial expression analysis. The proposed approach predicts both basic emotion and valence/arousal values as a continuous measure for the emotional state. Experimental results including cross-database evaluation on the AffectNet, Aff-Wild, and AFEW dataset shows that our approach predicts emotion categories and valence/arou...

Automatic understanding of facial behavior is hampered by factors such as occlusion, illumination, non-frontal head pose, low image resolution, or limitations in labeled training data. The EmotioNet 2020 Challenge addresses these issues through a competition on recognizing facial action units on in-the-wild data. We propose to combine multi-task an...

Current face detection concentrates on detecting tiny faces and severely occluded faces. Face analysis methods, however, require a good localization and would benefit greatly from some rotation information. We propose to predict a face direction vector (FDV), which provides the face size and orientation and can be learned by a common object detecti...

In this paper, we propose two simple yet effective methods to estimate facial attributes in unconstrained images. We use a straight forward and fast face alignment technique for preprocessing and estimate the face attributes using MobileNetV2 and Nasnet-Mobile, two lightweight CNN (Convolutional Neural Network) architectures. Both architectures per...

So far, all studies investigating the facial expression of pain have validated methods on the same database, whereas the cross-database performance is less considered. This may be due to poor performance of well-trained models on other databases. In this paper, we propose two distinct methods to classify based on the temporal information. To explor...

Experimental economic laboratories run many studies to test theoretical predictions with actual human behaviour, including public goods games. With this experiment, participants in a group have the option to invest money in a public account or to keep it. All the invested money is multiplied and then evenly distributed. This structure incentivizes...

Facial expression analysis is challenged by the numerous degrees of freedom regarding head pose, identity, illumination, occlusions, and the expressions itself. It currently seems hardly possible to densely cover this enormous space with data for training a universal well-performing expression recognition system. In this paper we address the sub-ch...

Facial expression analysis is challenged by the numerous degrees of freedom regarding head pose, identity, illumination, occlusions, and the expressions itself. It currently seems hardly possible to densely cover this enormous space with data for training a universal well-performing expression recognition system. In this paper we address the sub-ch...

Facial expression analysis is challenged by the numerous degrees of freedom regarding head pose, identity, illumination, occlusions, and the expressions itself. It currently seems hardly possible to densely cover this enormous space with data for training a universal well-performing expression recognition system. In this paper we address the sub-ch...

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Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verf...

Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verf...

The contact free camera-based estimation of human vital signs is more comfortable than the classical contact-based methods. Current methods suffer in realistic environments from e.g. occlusions by hair or glasses. Several approaches use complex methods to extract the pulse signals from the skin, but use basic geometric defined regions of the face,...

In this work we propose three applications towards an augmented reality-based machine operator assistance system. The application context is worker training in motor vehicle production. The assistance system visualizes information relevant to any particular procedure directly at the workplace. Mobile display devices in combination with augmented re...

Head pose estimation can help in understanding human behavior or to improve head pose invariance in various face analysis applications. Ready-to-use pose estimators are available with several facial landmark trackers, but their accuracy is commonly unknown. Following the goal to find the best landmark based pose estimator, we introduce a new databa...

Die kontaktfreie, kamerabasierte Messung von Vitalparameter des Menschen ist komfortabler als klassische kontaktbasierte Methoden. Aktuelle Verfahren haben jedoch noch Probleme in realistischen Anwendungsszenarien, z.B. bei Verdeckungen durch Haare oder Brillen. Zur Zeit werden zur Extraktion der nötigen Farbsignale geometrisch festgelegte Regionen...

Automatic Action Unit (AU) intensity estimation is a key problem in facial expression analysis. But limited research attention has been paid to the inherent class imbalance, which usually leads to suboptimal performance. To handle the imbalance, we propose (1) a novel multiclass under-sampling method and (2) its use in an ensemble. We compare our a...

Skin segmentation is widely used, e.g. in face detection and gesture recognition. In the last years, the number of skin seg-mentation approaches has grown. However, multiple datasets and varying performance measurements make direct compar-ison difficult. We address these shortcomings and evaluate 5 threshold-based methods, 5 model-based methods, an...

Using superpixels for color image segmentation is becoming increasingly popular, although it has not been utilized for skin segmenta-tion so far. In this paper we investigate the applications of superpixels for skin segmentation using the SLIC (Simple Linear Iterative Clustering) al-gorithm. We propose a novel approach that uses superpixels with a...

In this paper, a mobile assistance-system is described which supports users in performing manual working tasks in the context of assembling complex products. The assistance system contains a head-worn display for the visualization of information relevant for the workflow as well as a video camera to acquire the scene. This paper is focused on the i...

This paper focuses on real-time pedestrian detection on Field Programmable Gate Arrays (FPGAs) using the Histograms of Oriented Gradients (HOG) descriptor in combination with a Support Vector Machine (SVM) for classification as a basic method. We propose to process image data at twice the pixel frequency and to normalize blocks with the L1-Sqrt-nor...

In this paper, we present image-based methods for robust recognition of static and dynamic hand gestures in real-time. These methods are used for an intuitive interaction with an assistance-system in which the skin-tones are used to segment the hands. The segmentation builds the basis of feature extraction for the static and dynamic gestures. In th...

High computational costs and large memory requirements which are particularly relevant in embedded systems often result from a large support vector (SV) set of a non linear kernel support vector machine (SVM). We propose effective and straight forward methods, an improved RANSAC-SVM algorithm, called RANSAC-SV, and a novel algorithm SortedVotes, fo...