Area-energy aware dataflow optimisation of visual tracking systems

This paper presents an orderly dataflow-optimisation approach suitable for area-energy aware computer vision applications on FPGAs. Vision systems are increasingly being deployed in power constrained scenarios, where the dataflow model of computation has become popular for describing complex algorithms. Dataflow model allows processing datapaths comprised of several independent and well defined computations. However, compilers are often unsuccessful in identifying domain-specific optimisation opportunities resulting in wasted resources and power consumption. We present a methodology for the optimisation of dataflow networks, according to patterns often found in computer vision systems, focusing on identifying optimisations which are not discovered automatically by an optimising compiler. Code transformation using profiling and refactoring provides opportunities to optimise the design, targeting FPGA implementations and focusing on area and power abatement. Our refactoring methodology, applying transformations to a complex algorithm for visual tracking resulted in significant reduction in power consumption and resource usage

Measurement system for parameters evaluation of multi tone modulation with far-end crosstalk precompensation

Artykuł prezentuje wykonane stanowisko do badania i pomiarów parametrów transmisji wektorowej w systemie ADSL. Pozwala ono na sprzętową realizację transmisji wektorowej w kierunku od centrali do abonenta z użyciem 4 linii ADSL. Taki typ transmisji pozwala na prekompensację przeników występujących podczas transmisji w kablu wieloparowym.The paper describes system for evaluation and parameters measurement of vectorized ADSL transmission. Downstream transmission using 4 lines in vectored mode in ADSL standart is supported. Vectored transmission enables precompensation of crosstalk occuring between neighboring pairs in data cable

Image compression algorithm for wireless endoscopy capsule

Artykuł prezentuje algorytm kompresji obrazów planowany do zastosowania w bezprzewodowej kapsule ednoskopewj. Algorytm przeznaczony do tego typu zastosowań oprócz możliwie wysokiego stopnia kompresji musi cechować się bardzo niskim poborem mocy. To wymaganie wyklucza użycie standardowych metod. Proponowany algorytm oparty jest o całkowitoliczbowe wersje transformacji DCT i transformacji falkowej oraz koder Huffmana. W porównaniu do algorytmów konkurencyjnych proponowany algorytm oferuje znacznie większy stopień kompresji przy nieco większej (głównie pamięciowej) złożoności.The paper describes image compression algorithm suitable for wireless capsule endoscopy. Due to power limitation and small size conditions traditional image compression techniques are not appropriate and dedicated ones are neccessary. The proposed algorithm is based on integer version of discrete cosine transform (DCT) and wavelet transform (DWT) with Huffman entropy coder. Thanks to integer DCT/wavelet application it has low complexity and power consumption. Additionally, the algorithm can provide lossless compression as well as high-quality lossy compression

Integrated wideband transmitter for neural recording applications

W artykule przedstawiono projekt scalonego szerokopasmowego nadajnika dla systemu bezprzewodowej rejestracji potencjałów neuronowych. Prezentowany nadajnik został zaimplementowany w technologii CMOS 180 nm i pracuje w paśmie 4 GHz z modulacją OOK. Maksymalna oferowana szybkość transmisji sięga 80 Mb/s. Średni pobór mocy, przy szybkości transmisji 20 Mbit/s i zasięgu 4 m wynosi 1,8 mW. Struktura nadajnika zajmuje powierzchnie 0,4 x 0,75 mm2, na której oprócz elementów aktywnych mieszczą się cewki obwodu rezonansowego generatora LC i wzmacniacza RF. Napięcie zasilania układu wynosi od 1,5 V do 1,8 V, co pozwala na zasilanie nadajnika z jednej baterii pastylkowej. Układ sterujący nadajnika zaimplementowano w ultra niskomocowym układzie FPGA firmy Silicon Blue. Zawiera on kodera FEC, moduł przeplotu danych oraz kontroli mocy transmisji.The paper presents a low power integrated wideband telemetry system for neural recording. The presented system operates in 4 GHz band. It makes use of OOK modulation and offers very high data rate, up to 80 Mbits/s. The proposed system (Fig. 1) consists of an FPGA based controller and an an RF transmitter. The controller implements an FEC encoder, a bit interleaver, a scrambler and a pulse generator driving the RF transmitter. The FEC encoder is based on a bit-serial (233, 255) Reed-Solomon encoder. The scrambler is responsible for producing appropriate numbers of transitions in the transmitted signal to facilitate bit syn-chronization in the receiver. The RF transmitter was implemented in 180 nm CMOS process with an area of 0.4 x 0.75 mm2. It consumes 1.8 mW operating with the 20 Mbits/s data rate and the transmission range set to 4 m. All of the inductors were integrated on the transmit-ter silicon die, so the only external components are power supply bypass capacitors. For the experimental tests of the presented system a dedicated ultra wide-band antenna was designed on a 0.813 mm microwave substrate (Fig. 7). The radiating element (top layer) has dimensions of roughly 16 x 15 mm and the ground plane dimensions are 16 x 12 mm (bottom layer). The antenna features a very wide impedance band-width of 2.45 GHz (reflection coefficient below -10 dB) and operates in the frequency range 3.30 to 5.75 GHz. The antenna gain at the intended center frequency of the system, i.e. 4 GHz, is 2 dBi and VSWR is below 1.2. The accompa-nying receiver makes use of an AD8318 logarithmic detector

Heart segmentation in echo images

Cardiovascular system diseases are the major causes of mortality in the world. The most important and widely used tool for assessing the heart state is echocardiography (also abbreviated as ECHO). ECHO images are used e.g. for location of any damage of heart tissues, in calculation of cardiac tissue displacement at any arbitrary point and to derive useful heart parameters like size and shape, cardiac output, ejection fraction, pumping capacity. In this paper, a robust algorithm for heart shape estimation (segmentation) in ECHO images is proposed. It is based on the recently introduced variant of the level set method called level set without edges. This variant takes advantage of the intensity value of area information instead of module of gradient which is typically used. Such approach guarantees stability and correctness of algorithm working on the border between object and background with small absolute value of image gradient. To reassure meaningful results, the image segmentation is proceeded with automatic Region of Interest (ROI) calculation. The main idea of ROI calculations is to receive a triangle-like part of the acquired ECHO image, using linear Hough transform, thresholding and simple mathematics. Additionally, in order to improve the images quality, an anisotropic diffusion filter, before ROI calculation, was used. The proposed method has been tested on real echocardiographic image sequences. Derived results confirm the effectiveness of the presented method

New generation capsular endoscopy

W artykule przedstawiono wyniki prac realizowanych w ramach projektu VECTOR finansowanego w ramach 6 Programu Ramowego Unii Europejskiej w zakresie systemów kompresji i bezprzewodowej transmisji danych i obrazu dedykowanych dla endoskopii kapsułkowej nowej generacji. Opracowany system umożliwia transmisję 24 obrazów na sekundę o rozdzielczości 320x240 przez łącze radiowe o przepustowości 2 Mbit/s. Możliwość długotrwałej pracy kapsułki ma zapewnić układ zasilania bezprzewodowego zdolny dostarczyć do 300 mW mocy.The paper discusses the outcomes of the European Project VECTOR FP6 concerning image compression and wireless data transmission systems dedicated to a new generation of capsule endoscopy. The overview of the developed system is given in Section 2. The image compressor algorithm, developed within the project, is presented briefly in the first part of Section 3. Next, a new adaptive entropy encoder proposed for it is discussed in detail. The new encoder, in comparison to the previous one, has much lower memory footprint, as it does not use Huffman tables. Simulation results given in Tab. 1 clearly demonstrate that the new encoder, despite its low implementation complexity, outperform the old one. The developed image compressor algorithm was implemented in a single, 65 nm ultra low-power FPGA. It operates with 24 MHz clock and it is able to process a single image frame in 8.2 ms. Its energy consumption amounts to 0.4 mJ per single compressed frame. In Section 4 a wireless transmission system for wireless capsular endoscopy is presented. In this section an improved demodulator for a wireless receiver is also proposed. Section 5 contains the conclusions

Investigation of hardware and signal processing requirements for ECG analysis of Myocardial Infarction prediction

JOINT RESEARCH PROJECTS WITHIN THE XIX EXECUTIVE PROGRAMME OF SCIENTIFIC AND TECHNOLOGICAL CO-OPERATION BETWEEN ITALY AND POLAND FOR THE YEARS 2007-2009. The goal of this research is dual: to improve ultrasonic signal processing as they come out from the instrumentation and adding information so that it is possible to apply tomographic techniques with a basic purpose to diagnose, in early way, myocardial infarction, that is, circulatory coronary deficiency, not only when it clinically comes out, but to detect it before current instrumentations in use: Nuclear Magnetic Resonance, Cardial Axial Computerized Tomography, Coronary Angiography, myocardial Gamma camera and strain test

The simulation research of the model of broadband PLC transmission in home’s electrical systems 230/400 V AC

W artykule zamieszczono wyniki badań symulacyjnych szerokopasmowej transmisji modemowej w środowisku sieci energetycznej. Przedstawiono charakterystykę kanału PLC i występujących w nim zakłóceń. Wykonano eksperymenty mające na celu sprawdzenie możliwości wykorzystania popularnej techniki OFDM do transmisji sygnałów w kanale PLC.In this article simulation research of the model of broadband PLC broadband transmission in home’s electrical systems were performed. A short characterization of PLC channel and its disturbances was presented. Simulation experiments, which purpose was to investigate the possibility using of OFDM technique for data transmission in PLC channel, were performed