Browsing by Subject "kompresja obrazów"

Now showing 1 - 6 of 6

Access status: Metadata only ,
Image and contour data compression using periodic piecewise-linear transforms
(Data obrony: 1997) Belgassem, Fituri Hashmi
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
Access status: Open Access ,
Implementacja w układach FPGA kodeka obrazów w standardzie MPEG-2 spełniającego wymogi czasu rzeczywistego
(Data obrony: 2007-10-02) Dąbrowska, Agnieszka
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
The basic algorithms of video compression and decompression, which are components of encoder and de-coder of MPEG-2 standard, are described in doctoral the-sis. Moreover it contains the description of functionality as well as parameters of ISO/IEC 13818-2 standard. It contains the short description of previous examples of realization of MPEG-2 standard. The doctoral thesis contains the description of discrete cosine transform algorithms. Moreover it presents different aspects of hardware implementation of DCT blocks and received parameters. Proposed by author possible modifications of existing algorithms are described. These modifications have the adaptation of these algorithms to hardware implementation in programmable devices FPGA in view. It contains detailed description of quantisation and dequantisation operation in MPEG-2 standard taking control parameters of these operations under consideration. Moreover it presents possible ways of implementation of these operations. The basic algorithms of motion estimation are described. Implementations of two chosen algorithms of motion estimation as well as Three-Step Search algorithm modification are presented additionally. The algorithms of lossless video compression applied in encoders and decoders of standard MPEG2 as well as parameters of entropy encoder and decoder implementation in FPGA devices are presented. The descriptions and parameters of following versions of MPEG-2 standard encoders and codecs implemented in FPGA devices are also contained.
Access status: Metadata only ,
Kompresja obrazów stereoskopowych w przestrzeni Gabora
(Data obrony: 2000) Andrysiak, Tomasz
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
Access status: Restricted ,
Kompresja obrazów za pomocą transformaty ortogonalnej
(Data obrony: 2020-12-09) Kras, Łukasz
Wydział Informatyki, Elektroniki i Telekomunikacji
Access status: Open Access ,
Koncepcja fraktalnej kompresji obrazu
(Wydawnictwa AGH, 2006) Siwocha, Agnieszka; Krupski, Marcin; Cader, Andrzej
The advanced methods of picture compression treat the natural pictures as multifractal objects. In this paper there is proposed a distinct conception of fractal picture compression, which uses a new method of fractal interpolation. This method is based on a conception of fractal base splines and it is a modification of conventional method of base splines.
Access status: Open Access ,
Methods of contour compression in time and spectral domains
(Data obrony: 2007) Ukasha, Ali Abdrhman M.
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
Detailed analysis of the methods for contour data extraction has been given including the comparison between them using the number of operations versus the number of edges of the contour. The results approve that the fastest algorithm is the one which has the smallest size of windows. Six algorithms for contour data approximation in the time domain were proposed (centroid and segment distances ratio algorithms and triangle family which contains four algorithms), and compared with well known Ramer algorithm using mean square error, signal-to-noise ratio, compression ratio and the number of operations. Ali algorithms give CR more than 95% (the triangle family gives more than 97%). Except the first algorithm, their computational time of the approximating procedure is very short (i.e. many times faster than that of Ramer). Three algorithms for contour extraction (using high-pass filter) and image compression (using low-pass filter) using PHL transform were developed and compared with Sobel and Canny detectors. Two algorithms were presented for image reconstruction by contours extraction. The first algorithm using HPF and double transforms (two 1-dimensional and 2-dimensional PHL transform) while the second using two 1-dimensional PHL transform and only the most significant bit of the image.