Wyniki wyszukiwania - BazTech

1

Image acquisition system based on synchronized high-resolution gigabit ethernet cameras

Włodarczyk M., Kacperski D., Płuciennik T., Grabowski K.

Computer Science

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2017

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Vol. 18 (2)

179--194

EN

Over the past few years, a huge increase in the number of various computer vision applications can be observed. These are widely used in such areas as video surveillance, medical diagnostics, biometrics recognition, and the automotive and military industries. Most of these solutions take advantage of high-resolution cameras in order to obtain high-quality images. Surprisingly, little attention is paid in the literature to the practical implementation of off- the-shelf image acquisition systems. Most of the available solutions are composed of custom-developed electronic devices that use specialized multi-core DSPs and/or FPGA technology. Therefore, a novel realization of a scalable and comprehensive image acquisition system based on synchronized high-resolution Gigabit Ethernet cameras is presented in this paper. The proposed solution allows for the connection of multiple cameras along with any number of external illumination modules. The selected devices can be synchronized with each other in user-defined configurations; hence, a designed solution can be easily integrated in both simple and complex applications. The authors describe the design and implementation processes of the proposed platform in detail. The performance issues that can occur in such systems are presented and discussed. The obtained results are encouraging and useful for the development of similar solutions.

2

Calibration of vision systems operating in separate coordinate systems

Kacperski D., Sankowski W., Włodarczyk M., Grabowski K.

International Journal of Microelectronics and Computer Science

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2016

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Vol. 7, nr 1

10--15

EN

Over the last years, the use of multiple cameras is becoming more and more popular in today’s computer vision systems. Such approach is widely used in many applications, such as navigation of autonomous mobile robots, video surveillance, the movie industry, augmented reality or people tracking and identification systems. Surprisingly, little attention is paid in the literature to the practical calibration procedures that can be employed to map space between various vision systems. Therefore, in this paper a novel approach that allows to map space between cameras with different coordinate systems: Cartesian and polar is presented. The practical problems that occurs in such scenarios are analysed and thoroughly discussed. The authors present stepby-step description of the proposed calibration procedure. A series of experiments were conducted to confirm the correctness of the presented approach and to demonstrate how to apply the developed solution in practical applications. The proposed method does not require any additional equipment beyond the standard calibration chessboard. The achieved results indicate, that for evaluated cameras configuration, the maximum mapping error for the horizontal and vertical axes does not exceed 0.6°. Obtained results are encouraging and useful for development of similar solutions.

3

Inter-Device Periocular Recognition Under Near-Infrared Light

Włodarczyk M., Krotewicz P., Kacperski D., Sankowski W., Grabowski K.

Image Processing & Communications

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2016

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Vol. 21, no. 4

33--42

EN

Periocular biometrics is a relatively new field of research, and only several publications on this topic can be found in the literature. It can become a promising feature that can be used independently or as a complement to other biometrics. In this work, the recognition rates of periocular biometrics on a single acquisition device and inter-device database is verified and the impact of different image sources on the performance of recognition algorithms is investigated. For this purpose a NearInfrared Light database was collected. The database contains images taken by two acquisition devices. In order to test the periocular biometric trait, three feature extraction methods are chosen: Histograms of Oriented Gradients, Local Binary Patterns and Scale Invariant Feature Transform. The fusion of these methods is also proposed and it is tested on inter-device database. The feasibility of applying periocular recognition as an individual decision module for a biometric system is assessed. Experimental results yield Equal Error Rate of 17.65 for right eye using inter-device database of 640 gallery periocular images for each eye side taken from 32 different individuals (20 images per individual for each eye side). These results are obtained by the optimal weighted sum fusion of the three feature extraction methods.

4

Research on human silhouette detection methods for a non-cooperative biometric system

Kacperski D., Włodarczyk M., Grabowski K.

International Journal of Microelectronics and Computer Science

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2015

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Vol. 6, nr 1

10--13

EN

Together with the development of effective and efficient people identification algorithms, biometric authentication systems become increasingly popular and widespread, leading to a significant growth in the number of institutions interested in implementing and using such systems. Although, several research works focused their efforts on these type of solutions, none of the commonly available systems provide a non-cooperative approach to object identification. For this reason, they are not suitable for use in some specific situations, such as people entering the stadium. Therefore, we decided to go up against these limitations and develop biometric identification system for less constrained scenarios. In this paper, we present an evaluation of different algorithms suitable for human silhouette detection in such environment. We focus on investigating their effectiveness and performance under unconstrained conditions, such as different lighting.

5

Oparta o układy Spartan 6 wielokanałowa karta pomiarowo-sterująca w systemach sterowania piezoelektrycznych elementów wykonawczych

Przygoda K., Poźniak T., Kacperski D.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 7

668-670

PL

Prezentowany system umożliwia jednoczesną kompensację 16 wnęk rezonansowych zaopatrzonych w podwójne piezoelektryczne elementy wykonawcze. Pracę urządzenia nadzoruje nowoczesny układ reprogramowalny rodziny Spartan 6, umożliwiający nie tylko równoległe przetwarzanie sygnałów cyfrowych, ale także wymianę informacji cyfrowych z wykorzystaniem szybkich interfejsów szeregowych. Artykuł przedstawia pierwsze wyniki testów działania systemu po zainstalowaniu go w hali eksperymentalnej.

EN

The system presented in the paper allows simultaneous compensation of 16 resonant cavities equipped with double piezoelectric actuators, as depicted in Fig. 1. The device operation is assured by Spartan 6 FPGA equipped with digital signal processing units and fast serial links. The analog part of the system is based on a matrix of power amplifiers that allows driving the piezo elements with voltages up to š70 V. Since the piezo elements can be also used as mechanical vibration sensors, multichannel ADCs have been applied to provide fast data acquisition. The piezo actuator and sensor functionality can be exchanged remotely using switching relays. The input and output voltage as well as output current of the power amplifiers have been used for monitoring purpose. The piezo control system sends and receives data from the main signal processing unit (?TCA). The usage of fast serial links enables data throughput up to 125 Mb/s. The paper presents the results of the system performance measurements after its installation in a cryomodule test bench (CMTB). During the tests the main functionality of the module has been checked, as shown in Tab. 1. The system has been also used for adaptive compensation of cavity detuning during RF pulse operation with accelerating field gradients up to 18 MV/m (see Fig. 7). The presented solution will be applied in the incoming X-Ray Free Electron Laser