Tomasz Grzejszczak

Wrist Localization in Color Images for Hand Gesture Recognition

In this paper we present an extensive study of a two-stage algorithm for wrist localization in color images, which is an important and challenging, yet not extensively studied, step in gesture recognition systems. In the first stage of the algorithm, a color hand image is subject to skin segmentation. Secondly, the wrist is localized in a corresponding binarized skin probability map. In our two-stage approach, the algorithms for both localization stages can be developed and compared separately. Here, we compare our propagation-based skin segmentation algorithm and real-time wrist localization algorithm with other state-of-the-art approaches based on our set of 414 color hand images using two independent sets of ground-truth data.

Gesture based robot control

The paper proposes a method of controlling robotic manipulators with use of human gestures and movement. Experiments were performed with the use of 4 degree-of-freedom AX-12 Robotic Arm manipulator with force gripper and ASUS Xtion depth sensor also called motion controller. Depth and video capture has been done via OpenNI library. The infrastructure is based on Windows Communication Foundation (WCF) for remote access, authorization, multimedia streaming and servo control. Control of robotic manipulator is implemented with use of human computer interaction algorithm basing on depth sensor information.

A prototype device for concealed weapon detection using IR and CMOS cameras fast image fusion

Concealed weapon detection (CWD) is an important part of everyday law enforcement. There are numerous facilities that are endangered of an terrorist or an fanatic individual attack. Commercially used weapon detection gates are very expensive and sometimes impossible to install into already existing security infrastructures. Here we present a miniature prototype device for concealed weapon detection using two cameras: IR and visual. The prototype consists of two printed circuit boards (PCB). First PCB is responsible for analog to digital and digital to analog conversions of the video stream. The second board is the main processing unit realizing the presented fast image fusion algorithm. The relative size of the prototype can be assumed as a miniature in comparison to the current used solutions. Such miniature device could be mounted under the ceiling or inside 3 DOF gimbals for wider view angle. Presented device can be considered as an alternative to already existing man-sized gates traditionally used for CWD.

Hand landmarks detection and localization in color images

This paper introduces a new method for detecting and localizing hand landmarks in 2D color images. Location of the hand landmarks is an important source of information for recognizing hand gestures, effectively exploited in a number of recent methods which operate from the depth maps. However, this problem has not yet been satisfactorily solved for 2D color images. Here, we propose to analyze the skin-presence masks, as well as the directional image of a hand using the distance transform and template matching. This makes it possible to detect the landmarks located both at the contour and inside the hand masks. Moreover, we performed an extensive experimental study to compare the proposed method with a number of state-of-the-art algorithms. The obtained quantitative and qualitative results clearly indicate that our approach outperforms other methods, which may help improve the existing gesture recognition systems.

Robot Manipulator Teaching Techniques with Use of Hand Gestures

Robot manipulator teaching is a time consuming procedure where qualified operator programs the execution path. In this paper we introduce and discuss the improvement of traditional teaching method with application of hand gesture recognition system. The paper presents the most common robot programming and hand gesture recognition issues and presents the possibility of joining this two research fields.

Real-Time Wrist Localization in Hand Silhouettes

This paper is focused on wrist localization which is an important step in recognizing hand gestures. While there are many methods for detecting hand feature points as well as for estimating the hand pose, the majority of them assume that the palm region is given and ignore the wrist detection step. However, despite it is a required operation if the gesture recognition is supposed to be automatic, wrist localization has not been given much attention in the literature. Here, we propose a fast, yet effective method for wrist localization and we present the evaluation procedure based on our set of 899 hand images with ground-truth data. To the best of our knowledge, such a quantitative analysis of this problem has not been published so far.

An Approach to Control of Human Leg Switched Dynamics

This article describes the approach to control of human leg dynamical model as a switched linear system. The control scheme consists of fractional and integral order PID controllers. In the paper we analyze the responses of the system depending on the above-mentioned controllers. We focus our attention on angular displacements only. The angular velocity maybe arbitrary. Additionally, we present the method how to design a human leg as the switched linear system. In this case the switching rule is state-dependent. Finally, we present two illustrative examples for two different trajectories.

Comparison of Hand Feature Points Detection Methods

This paper presents the research and comparison of four methods of hand characteristic points detection. Each method was implemented and modified in order to test their capabilities on database for hand gesture recognition. All methods are explained, tested and compared to others with other leading to final remarks. The main purpose of the research is to choose the best algorithm giving the most information about human hand that would lead to create a human – computer interaction program.

Controllability of discrete-time switched fractional order systems

In the article unconstrained controllability problem of discrete-time switched fractional order systems is addressed. A solution of discrete-time switched fractional order state equation is presented. Additionally, a transition matrix of considered dynamical systems is given. A sufficient condition for unconstrained controllability in a given time interval is formulated and proved by the general formula of difference state equation solution. At the end, an illustrative example is also shown.

Automatic Targeting Sentry Turret for Distributed Systems

Today most popular systems are constructed with the idea of collaboration. In software we can see a drastic increase of cloud-oriented applications, in electronics more devices are designed with CAN and Ethernet communications, and in robotics and defense whole systems are linked as unmanned sensor and agent networks. This paper describes the fundamental design principles of an automatic sentry turret in a distributed multi-agent system. The work is focused on the design of the turret system itself and the system architecture for distributed robotic applications. The papers is divided into the following sections: introduction, turret construction, system architecture, automatic target detection and aiming, and summary. Module.