Embed[d]ed Zerotree Codec

This thesis discusses the findings of the final year project involving the VHDL (V= Very High Speed Integrated Circuit, Hardware Description Language) design and simulation of an EZT (Embedded Zero Tree) codec. The basis of image compression and the various image compression techniques that are available today have been explored. This provided a clear understanding of image compression as a whole. An in depth understanding of wavelet transform theory was vital to the understanding of the edge that this transform provides over other transforms for image compression. Both the mathematics of it and how it is implemented using sets of high pass and low pass filters have been studied and presented. At the heart of the EZT codec is the EZW (Embedded Zerotree Wavelet) algorithm, as this is the algorithm that has been implemented in the codec. This required a thorough study and understanding of the algorithm and the various terms used in it. A generic single processor codec capable of handling any size of zerotree coefficients of images was designed. Once the coding and decoding strategy of this single processor had been figured out, it was easily extended to a codec with three parallel processors. This parallel architecture uses the same coding and decoding methods as in the single processor except that each processor in the parallel processing now handles only a third of the coefficients, thus promising a much speedier codec as compared to the first one. Both designs were then translated into VHDL behavioral level codes. The codes were then simulated and the results were verified. Once the simulations were completed the next aim for the project, namely synthesizing the design, was embarked upon. Of the two logical parts of the encoder, only the significance map generator has been synthesized

An overview of JPEG 2000

JPEG-2000 is an emerging standard for still image compression. This paper provides a brief history of the JPEG-2000 standardization process, an overview of the standard, and some description of the capabilities provided by the standard. Part I of the JPEG-2000 standard specifies the minimum compliant decoder, while Part II describes optional, value-added extensions. Although the standard specifies only the decoder and bitstream syntax, in this paper we describe JPEG-2000 from the point of view of encoding. We take this approach, as we believe it is more amenable to a compact description more easily understood by most readers.

Data compression in smart distribution systems via singular value decomposition

Electrical distribution systems have been experiencing many changes in recent times. Advances in metering system infrastructure and the deployment of a large number of smart meters in the grid will produce a big volume of data that will be required for many different applications. Despite the significant investments taking place in the communications infrastructure, this remains a bottleneck for the implementation of some applications. This paper presents a methodology for lossy data compression in smart distribution systems using the singular value decomposition technique. The proposed method is capable of significantly reducing the volume of data to be transmitted through the communications network and accurately reconstructing the original data. These features are illustrated by results from tests carried out using real data collected from metering devices at many different substations

Combined Industry, Space and Earth Science Data Compression Workshop

The sixth annual Space and Earth Science Data Compression Workshop and the third annual Data Compression Industry Workshop were held as a single combined workshop. The workshop was held April 4, 1996 in Snowbird, Utah in conjunction with the 1996 IEEE Data Compression Conference, which was held at the same location March 31 - April 3, 1996. The Space and Earth Science Data Compression sessions seek to explore opportunities for data compression to enhance the collection, analysis, and retrieval of space and earth science data. Of particular interest is data compression research that is integrated into, or has the potential to be integrated into, a particular space or earth science data information system. Preference is given to data compression research that takes into account the scien- tist's data requirements, and the constraints imposed by the data collection, transmission, distribution and archival systems

Development of algorithm for identification of maligant growth in cancer using artificial neural network

The precise identification and characterization of small pulmonary nodules at low-dose CT is a necessary requirement for the completion of valuable lung cancer screening. It is compulsory to develop some automated tool, in order to detect pulmonary nodules at low dose ct at the beginning stage itself. The numerous algorithms had been proposed earlier by many researchers in the past, but, the accuracy of prediction is always a challenging task. In this work, an artificial neural network based methodology is proposed to find the irregular growth of lung tissues. Higher probability of detection is taken as a goal to get an automated tool, with great accuracy. The finest feature sets derived from Haralick Gray level co occurrence Matrix and used as the dimension reduction way for feeding neural network. In this work, a binary Binary classifier neural network has been proposed to identify the normal images out of all the images. The capability of the proposed neural network has been quantitatively computed using confusion matrix and found in terms of classification accuracy

Nonrectangular wavelets for multiresolution mesh analysis and compression

We propose a new Set Partitioning In Hierarchical Trees (SPIHT) based mesh compression framework. The 3D mesh is first transformed to 2D images on a regular grid structure. Then, this image-like representation is wavelet transformed and SPIHT is applied on the wavelet domain data. The method is progressive because the resolution of the reconstructed mesh can be changed by varying the length of the ID data stream created by SPIHT algorithm. Nearly perfect reconstruction is possible if full length of 1D data is received

Primitives and design of the intelligent pixel multimedia communicator

Communication systems arc an ever more essential component of our modern global society. Mobile communications systems are still in a state of rapid advancement and growth. Technology is constantly evolving at a rapid pace in ever more diverse areas and the emerging mobile multimedia based communication systems offer new challenges for both current and future technologies. To realise the full potential of mobile multimedia communication systems there is a need to explore new options to solve some of the fundamental problems facing the technology. In particular, the complexity of such a system within an infrastructure framework that is inherently limited by its power sources and has very restricted transmission bandwidth demands new methodologies and approaches

Analysis and techniques of data compression in smart grids in the context of IEC 61850 communication protocol

A smart grid is characterized by a two-way communication between the generation and the loads in addition to the distributed energy resources, which dictated the integration of smart monitoring devices to achieve full observability of the network. In smart grid operation, the monitoring and the measuring devices such as smart meters, phasor measurement units (PMUs) and the intelligent electronic devices (IEDs) typically record the data and share the information across each level of the grid. In distribution substations, the data and hence the information is then further transferred throughout the supervisory control and data acquisition (SCADA) and the data control center using the communication protocols. As a result, a large amount of data is transferred among different monitoring devices, data control centers, and SCADA within the smart grid, which calls for new requirements for the communication channels and the storage capacities. Data compression is considered promising techniques to reduce the burden on the communication channels as well as the storage in particular during the smart grid operation. This thesis focuses on studying the data compression techniques when applied to power system disturbances in the context of the IEC 61850 communication protocol, which is extensively used in smart distribution substation automation. A proposed approach for data compression is introduced in this work and it is based on a combined wavelet-surrogate binary regression tree and a hybrid thresholding method. The proposed approach for data compression is tested experimentally in real-time in the context of IEC 61850 communication protocol and the performance is compared to the existing approaches for data compression. The results have shown that the implementation of the proposed data compression approach may lead to significant reduction in the number and sizes of the Generic Object-Oriented Substation Event (GOOSE) messages, which are exchanged between the IEDS and the SCADA within the smart distribution substation automation in smart grids