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Imaging of fluorescence emission signals from healthy and infected leaf tissues
BENEDIKTYOVÁ, Zuzana
Auto-fluorescence emission of plant tissues can be a powerful reporter on plant biochemistry and physiology since it originates in substances inherent to primary or secondary metabolism. Plant bodies contain a plethora of intrinsic fluorescent compounds emitting practically all wavelengths of visible light. Moreover, the spectrum of fluorescent reporter signals was recently extended by a variety of fluorescent proteins that provide a new tool to mark whole cells or sub-cellular structures, study protein localization and monitor gene expression and molecule interactions. The imaging of such fluorescence signals reveals a possibility to acquire the information from as many as millions of points simultaneously, in vivo and in a non-invasive way thereby preserving integrity of cells and whole organisms. Imaging is particularly suited to visualize heterogeneity such as a localized immune response to invading pathogens. It can be applied both at macro- as well as micro-scales in two and three dimensions. The recent advancement in microscopy, the multi-photon microscopy, has made possible to monitor fluorescence signals, such as NAD(P)H fluorescence from intact leaf interior, that have been hidden to single-photon techniques.
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Processing flow visualisation records by correlation coefficient evaluation in sub-images
Tesař, Václav ; Něnička, Václav
Authors introduced a new method of processing flow visualisation images,aiming at identification of instability structures. In principle, the method utilises the structures' coherence. In two digital images, recorded at slightly differentinstants of time, the pixel pairs from the same position in the images are interrogated one by one. In each, vectors of the recorded quantity values are formed from n x n pixels in immediate neighbourhood, which form the sub-image. The correlation coefficient is then computed for the vector pair. High positive values of the coefficient indicate absence of change whereas values near zero indicate chaotic changes. Of interest are negative values, which indicate a coherent motion.
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Použití Matlabu pro kvantitativní analýzu růstu kvasinek
Schier, Jan ; Kovář, Bohumil
Quantitative growth analysis is used in microbiology, genetics and medical re- search to determine the in uence of the tested substance on the growth of colonies of some organism (we focus on yeast colonies in this paper). Examples of the tested substance include antibiotics, mutagens or medical drugs. To evaluate the experiment, time series of images of the colonies inoculated on Petri dishes are taken by digital camera in a darkroom. Then, relative area and the number of the colonies in each image have to be determined for further statistical processing. In the current laboratory practice, these parameters have often been hand-counted in each image, which is an error-prone process of a limited precision. Also, given the time demands of this hand-counting, the number of snapshots that can reasonably be processed is rather limited. In this paper, we introduce a Matlab-based tool for semi-automated processing of the dish images.
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Special Issue on the 18th International Conference on Artificial Neural Networks
Húsek, Dušan ; Neruda, Roman ; Koutník, J.
Special Issue on the 18th International Conference on Artificial Neural Networks. Neural Network World. Vol. 19, No. 5 (2009). The issue contains papers prepared specially for this issue by authors of some best evaluated papers presented on ICANGA 2008 conference. Covered are mainly following topics: Mathematical Theory of Neurocomputing, Computational Neuroscience, Connectionist Cognitive Science, Neuroinformatics, Image Processing, Signal and Time Series Processing, Reinforcement Learning, Binary Factor Analysis, Principal Component Analysis, Self-organization, Neural Network Hardware.
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Výzkum vlivu množství argony na stabilitu proudu Ar-H-O plazmatu
Chumak, Oleksiy ; Kavka, Tetyana ; Hrabovský, Milan
The paper examines an effect of an argon amount on the thermal plasma jet generated from water/argon mixture in a dc arc plasma torch. In spite of an increase of plasma velocity with an addition of argon a decrease of plasma jet length is observed for bigger argon amount in the plasma. The investigation was based on an analysis of a jet structure based on imaging of the plasma jet by a CCD camera. Statistical processing of plasma jet photographs provided information about a jet shape and its fluctuations space distribution. It was found that an argon amount increase caused significant intensification of the plasma jet fluctuations.
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Periodické vlastnosti převzorkovaných obrazů
Mahdian, Babak ; Saic, Stanislav
In recent years, due to the advent of high-performance commodity hardware and improved human computer interfaces, it has become relatively easy to create fake images. Modern, image processing software enables forgeries that are undetectable by the naked eye. Typically, to create high quality and consistent forgeries, several types of tampering techniques are employed simultaneously. One of the most often used techniques is resampling. When two or more images are spliced together, in order to create a consistent tampering, almost always geometric transformations such as scaling or rotation are needed. In this work we propose an effective method to automatically detect resampled portion of images. Generally, resampling is based on an interpolation procedure. We study specific periodic properties presence in interpolated signals and use this for our detection method. We demonstrate our results on several examples.
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