This report presents an algorithm for locating the cut points for and separatingvertically attached traffic signs in Sweden. This algorithm provides severaladvanced digital image processing features: binary image which representsvisual object and its complex rectangle background with number one and zerorespectively, improved cross correlation which shows the similarity of 2Dobjects and filters traffic sign candidates, simplified shape decompositionwhich smoothes contour of visual object iteratively in order to reduce whitenoises, flipping point detection which locates black noises candidates, chasmfilling algorithm which eliminates black noises, determines the final cut pointsand separates originally attached traffic signs into individual ones. At each step,the mediate results as well as the efficiency in practice would be presented toshow the advantages and disadvantages of the developed algorithm. Thisreport concentrates on contour-based recognition of Swedish traffic signs. Thegeneral shapes cover upward triangle, downward triangle, circle, rectangle andoctagon. At last, a demonstration program would be presented to show howthe algorithm works in real-time environment.

Yes / The efficiency and acquisition of a clean (diagnosable) ECG signal dependent upon the proper selection of electronic components and the techniques used for noise elimination. Given that the human body and the lead cables act as antennas, hence picking up noises from the surroundings, thus a major part in the design of an ECG device is to apply various techniques for noise reduction at the early stage of the transmission and processing of the signal. This paper, therefore, covers the design and development of a Single Chanel 3-Lead Electrocardiograph and a Software-based processing environment. Main design characteristics include reduction of common mode voltages, good protection for the patient, use of the ECG device for both monitoring and automatic extraction (measurements) of the ECG components by the software. The hardware consisted of a lead selection stage for the user to select the bipolar lead for recording, a pre-amplification stage for amplifying the differential potentials while rejecting common mode voltages, an electrical isolation stage from three filtering stages with different bandwidths for noise attenuation, a power line interference reduction stage and a final amplification stage. A program in LabVIEW was developed to further improve the quality of the ECG signal, extract all its features and automatically calculate the main ECG output waveforms. The program had two main sections: The filtering section for removing power line interference, wideband noises and baseline wandering, and the analysis section for automatically extracting and measuring all the features of the ECG in real time. A Front Panel Environment was, therefore, developed for the user interface. The present system produced ECG tracings without the influence of noise/artefacts and provided accurate detection and measurement of all the components of the ECG signal.

No description available.

Medical ultrasound is one of the most used tools for obtaining diagnostic, being a noninvasive technique, with high efficiency, low cost and real-time visualization. But these images are usually contaminated with a type of multiplicative noise known as speckle noise. This noise superimposed on the image granules that distorts and complicates the analysis of the diagnosis. Despite the removal of multiplicative noises has not been studied so extensively as the elimination of additive noise, there are some works that propose solutions to eliminate this type of noise, including works using variational methods. The variational methods have a smoothing term and a fidelity term, which are responsible for smoothing and preserving image characteristics, respectively. Typically, a balance is made between these two terms that will be used for all pixels in the image. This report will propose a variational method in order to reduce speckle noise in ultrasound images. The differential of the proposed method over other methods is the inclusion of a function in order to detect the locations of pixels with high noise level and pixels containing edges, ie, important features of the image that should be preserved. The function will adjust the fidelity and smoothing of the functional, so that this balance causes smoothing to be more severe in very noisy pixels and fidelity is more intense at the image edges. / Ultrassonografia médica é uma das ferramentas mais utilizadas para obtenção de diagnósticos, por ser uma técnica não invasiva, com alta eficácia, baixo custo e visualização em tempo real. Porém essas imagens normalmente são contaminadas com um tipo de ruído multiplicativo, conhecido como ruído speckle. Esse ruído sobrepõe granulações na imagem de forma que a distorce e dificulta a análise do diagnóstico. Apesar da eliminação de ruídos multiplicativos não ter sido estudada de forma tão extensiva quanto a eliminação de ruídos aditivos, existem alguns trabalhos que propõem soluções para eliminação deste tipo de ruído, incluindo trabalhos que usam de métodos variacionais. Os métodos variacionais possuem um termo de suavização e um termo de fidelidade, que são responsáveis por suavizar e preservar características da imagem, respectivamente. Normalmente, é feito um balanceamento entre esses dois termos que será utilizado em todos os pixels da imagem. Neste trabalho será proposto um método variacional com o objetivo de reduzir ruídos speckle em imagens de ultrassonografia. O diferencial do método proposto em relação a outros métodos, é a inclusão de uma função com o objetivo de detectar as localizações dos pixels com alto nível de ruído e dos pixels que contenham bordas, ou seja, características importantes da imagem que devem ser preservadas. Assim, a função irá ajustar a fidelidade e suavização do funcional, de forma que este balanceamento faça com que a suavização seja mais intensa em pixels bastante ruidosos e a fidelidade seja mais intensa em bordas da imagem. / Mestre em Ciência da Computação

科学研究費補助金 研究種目:試験研究 課題番号:63850078 研究代表者:日比野 倫夫 研究期間:1988-1989年度