Image Compression Using the Wavelet Transform

Tato práce se zabývá problematikou komprese obrazu pomocí vlnkové transformace. První část tohoto dokumentu poskytuje čtenáři informace o problematice komprese obrazu, představuje nejznámější současné postupy a detailněji probírá vlnkovou transformaci a následná kódování. Jsou představeny standardy JPEG a JPEG 2000. Vdruhé části se rozebírá způsob implementace, inovativní postupy a optimalizace. Třetí část je věnována srovnání a vyhodnocení dosažených výsledků.This thesis is focused on subject of image compression using wavelet transform. The first part of this document provides reader with information about image compression, presents well known contemporary algorithms and looks into details of wavelet compression and following encoding schemes. Both JPEG and JPEG 2000 standards are introduced. Second part of this document analyzes and describes implementation of image compression tool including inovations and optimalizations. The third part is dedicated to comparison and evaluation of achievements.

Comparison of Video Codecs

Tato práce se zabývá analýzou videokodeků a jejich srovnáním. První část tohoto dokumentu poskytuje čtenáři základní informace o problematice kódování a dekódování videa, dále přibližuje jednotlivé kodeky a problematiku standardizace. Jsou představeny transformace jako DCT a DWT, dále intra a inter snímková predikce a entropická kódování. Druhá část je zaměřena na návrh testování a konkrétní srovnání včetně vyhodnocení. K samotném srovnání jsou použity metody PSNR, SSim a BD-PSNR.This thesis is aimed at analysis of video codecs and their comparison. First part of this document provides reader with the basic information on encoding and decoding process including high level description of often used algorithms. It describes codecs and the process of standardization. Second part is focused on test specifications and codecs comparsion itself including conclusion. PSNR, SSim and BD-PSNR are key methods used for comparing codecs.

Photolitography on flexible substrates

Nowadays preparation of structures on flexible substrates is highly demanded because of using this patterns in field of flexible electronics. This contribution deals with photolitographic procces for preparation of structures on flexible substrates. The method of photolitography enables to create designed patterns in various material (e.g. metals as conductive layers) on various substrates (silicon wafers, foils, etc.). First the designed pattern is exposed through the mask by UV light into polymer resist, then the pattern is transfered into metal layer by wet etching through the developed windows in resist. In this paper several patterns are prepared through the positive resist PMMA by photolitography into various metal layer (Cu, Al) on flexible substrates. © 2018 TANGER Ltd. All Rights Reserved.Ministry of Education, Youth and Sports of the Czech Republic - program NPU I [LO1504]; Operational Program Research and Development for Innovations - European Regional Development Fund (ERDF); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409

Patterning of self-assembled monolayers (SAMS)

Self-assembled monolayers (SAMs) has recently received much attention because of their wide range in applications such as layers in biosensors, electronic active layers or interlayers in organic electronic devices like organic light emitting diodes (OLEDs), organic photovoltaics (OPVs), organic thin film transistors (OTFTs). Photolithography is a basic and long established technique used in the preparation of processors and other electronic components. This paper deals with patterning of self-assembled monolayers prepared on gold and silver layers using photolithography. Firstly, the prepared self-assembled monolayers were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Fourier-transform infrared spectroscopy (FTIR). Subsequently testing patterns according to the resolution chart test were exposed by UV lithography. These prepared patterns were characterized by optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). © NANOCON 2019.All right reserved.Ministry of Education, Youth and Sports of the Czech Republic Program NPU I [LO1504]; Operational Program Research and Development for Innovations - European Regional Development Fund (ERDF); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409

Thickness dependent structural ordering, degradation and metastability in polysilane thin films: A photoluminescence study on representative σ-conjugated polymers

We present a fundamental experimental study based on the fluorescence investigation of thin σ-conjugated polymer films, where the dependence of optoelectrical properties and UV degradation on film thickness ranging from nano- to microscale was studied. Such extensive and detailed study was performed for the first time and observed spectral shifts in emission and excitation spectra and UV degradation retardation point towards the conclusions that there exists a threshold thickness where the material degradation behavior, electron delocalization and structure suddenly change. The development of well aligned polymeric chain structure between the nano- and micrometer thickness (on the mesoscale) was shown responsible for the manifested phenomena. The material thicker than critical 500 nm has extremely small Stokes' shift, maximum extended σ-delocalization along the silicon polymer backbone and exhibits remarkable UV degradation slowdown and self-recovery ability. On the contrary, the electronic properties of thin films below 80 nm resemble those of random coils in solutions. The films of moderate thickness show relatively steep transition between these two modes of structural ordering and resulting properties. Altogether, we consider this complex phenomenon as a consequence of the mesoscale effect, which is an only recently introduced concept in polymer thin films. © 2015 Elsevier B.V. All rights reserved.Operational Programme 'Research and Development for Innovations'; European Regional Development Fund (ERDF); National Budget of the Czech Republic within the project 'Centre of Polymer Systems' [CZ.1.05/2.1.00/03.0111]; Operational Programme 'Education for Competitiveness'; European Social Fund (ESF); National Budget of the Czech Republic, within the project 'Advanced Theoretical and Experimental Studies of Polymer Systems' [CZ.1.07/23.00/20.0104]; Ministry of Education, Youth and Sports of the Czech Republic - Program NPU I [LO1504

Microstrip antenna from silver nanoparticles printed on a flexible polymer substrate

This work describes the use of inkjet printing technology to fabricate a flexible microstrip antenna. The antenna is printed on a flexible PET foil (Polyethylene terephthalate) using silver nanoparticles. Silver nanoparticles were synthetized by the solvothermal precipitation technique. The diameter of the prepared silver nanoparticles ranges from 20 to 200 nm measured with the help of the SEM analysis. In addition, the ink formulation for printing of a homogenous and electrically conductive layer was further prepared using silver nanoparticles. The printed antenna operates in two frequency bands of 2.02 GHz (-16.02 db) and 2.3 GHz (-19.33 db). The antenna is flexible and weigh is only 0.208 g and is suitable for electronic devices of a very low weight, such as wearable electronic devices. © 2017 Elsevier Ltd.Ministry of Education, Youth and Sports of the Czech Republic - National Sustainability Program NPU I [LO1504]; Operational Program Research and Development for Innovations; European Regional Development Fund (ERDF); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409

Poly(vinyl alcohol): formulation of a polymer ink for the patterning of substrates with a drop-on-demand inkjet printer

Nowadays, inkjet-printing technology is considered one of the most promising deposition techniques. It allows the highly precise deposition of functional materials to the required place on a substrate and a cost-saving printing process, especially when the drop-on-demand manner is used. Moreover, it represents the perfect technique for the controlled deposition of polymer material, especially for polymer solutions, because of their low viscosity and better process ability. Poly(vinyl alcohol) was chosen because of its versatile application potential; moreover, its compatibility with the human body only increases its usability in bio-applications. The main purpose of this research was to find the appropriate solvent system for poly(vinyl alcohol) and its printability. Solutions with the best properties were printed in pre-defined patterns and personally defined motifs and the printing conditions were optimized in order to obtain patterns with the best possible shape and resolution, which were analysed by optical microscopy.Ministry of Education; Youth and Sports of the Czech Republic - Program NPU I [LO1504]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2015/006

Cross sectioning of optoelectronic device

Optoelectronic devices play very important role in life nowadays. Most of the devices are widely used in fields ranging from image processing and fiber optic communication to common consumer electronics (twilight switches, house security systems, etc.), where components such as photodiodes, laser diodes, phototransistors, photomultipliers, optical isolators, LEDs or OLEDs are mounted. Accurate procedure is necessary during the preparation to achieve their fully functionality. Because the devices are mostly prepared as multilayer systems, there is a requirement for correct functional thickness of layers. The thickness of the layers could be checked not only during the deposition but also retrospectively in the case of some failures during their deposition. The method of ion beam milling can be used for cross section preparation and can achieve cross sections of soft materials or material combinations consisting of hard and soft components, which are used in devices. This contribution deals with case study of SEM thickness layer characterization of optoelectronic device on cross section, which was prepared by ion milling.ERDF, European Regional Development FundOperational Program Research and Development for Innovations; European Regional Development Fund (ERDF); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409]; Ministry of Education, Youth and Sports of the Czech Republic program NPUI [LO1504

Facile microwave-assisted synthesis of casein derived carbon nanodots

Belonging to the carbon family, yet standing apart, carbon nanodots are materials with excellent properties. Among them, they are well known for their attractive optical properties. The insight into this outstanding strength has resulted in the discovery of unique design of materials. These nanodots can be prepared via various methods to obtain a good optical response. In our research, we synthesized them using a microwave reactor, which is simple, fast and productive. As a carbon source casein, a low-cost precursor was used. Since this is a protein composed of amino acids, no additional passivation was required. Polyvinylpyrrolidone was used as a stabilizer for the nanodots. The synthesis was carried out at 200 °C for 30 minutes. The color change of the resulting solution to orange brown indicates the formation of carbon nanodots. These nanodots were filtered and dialyzed to be used for further characterizations. The carbon nanodots were spherical with the average size of about 9.7 nm. They showed a strong blue emission in the visible region with an appreciable quantum yield. One of the important characteristics of this method is the availability of reasonably good product yield. The prepared carbon nanodots have potential applications in the field of electrochemistry, optoelectronics and biological imaging. © 2021 TANGER Ltd., Ostrava.Ministry of Education, Youth and Sports of the Czech Republic Program-DKRVO [RP/CPS/2020/006]RP/CPS/2020/00