Wavelet Theory

The wavelet is a powerful mathematical tool that plays an important role in science and technology. This book looks at some of the most creative and popular applications of wavelets including biomedical signal processing, image processing, communication signal processing, Internet of Things (IoT), acoustical signal processing, financial market data analysis, energy and power management, and COVID-19 pandemic measurements and calculations. The editor’s personal interest is the application of wavelet transform to identify time domain changes on signals and corresponding frequency components and in improving power amplifier behavior

FACE, GENDER AND RACE CLASSIFICATION USING MULTI-REGULARIZED FEATURES LEARNING

This paper investigates a new approach for face, gender and race classification, called multi-regularized learning (MRL). This approach combines ideas from the recently proposed algorithms called multi-stage learning (MSL) and multi-task features learning (MTFL). In our approach, we first reduce the dimensionality of the training faces using PCA. Next, for a given a test (probe) face, we use MRL to exploit the relationships among multiple shared stages generated by changing the regularization parameter. Our approach results in convex optimization problem that controls the trade-off between the fidelity to the data (training) and the smoothness of the solution (probe). Our MRL algorithm is compared against different state-of-the-art methods on face recognition (FR), gender classification (GC) and race classification (RC) based on different experimental protocols with AR, LFW, FEI, Lab2 and Indian databases. Results show that our algorithm performs very competitively

Spline wavelet image coding and synthesis for a VLSI based difference engine

Bibliography: leaves 142-146.The efficiency of an image compression/synthesis system based on a spline multi-resolution analysis (MRA) is investigated. The proposed system uses a quadratic spline wavelet transform combined with minimum-mean squared error vector quantization to achieve image compression. Image synthesis is accomplished by utilizing the properties of the MRA and the architecture of a custom designed display processor, the Difference Engine. The latter is ideally suited to rendering images with polynomial intensity profiles, such as those generated by the proposed spline :V1RA. Based on these properties, an adaptive image synthesis system is developed which enables one to reduce the number of instruction cycles required to reproduce images compressed using the quadratic spline wavelet transform. This adaptive approach is computationally simple and fairly robust. In addition, there is little overhead involved in its implementation

Penggunaan Arnold Cat Map Dan Beta Chaotic Map Pada Enkripsi Data Citra

Penggunaan citra dalam kehidupan sehari-hari mengalami peningkatan seiring berkembangnya teknologi informasi. Untuk itu diperlukan sebuah cara agar data citra dapat ditransmisikan dengan aman. Salah satunya adalah dengan melakukan enkripsi pada citra. Citra terenkripsi akan membuat citra hanya dapat dibaca oleh pihak yang berwenang saja. Skema yang digunakan pada proses enkripsi dapat berupa permutasi. Pada penelitian ini menggunakan Arnold cat map untuk melakukan permutasi pada enkripsi citra. Namun permutasi saja tidak cukup aman untuk mengenkripsi citra. Citra yang telah dipermutasi selanjutnya ditambah dengan algoritma lain berbasis chaos. Beta chaotic map digunakan dalam penelitian ini karena memiliki parameter yang lebih banyak dibandingkan dengan map jenis lain. Dengan parameter yang lebih besar maka akan memperkuat hasil enkripsi. Hasil pengujian yang dilakukan pada penelitian ini menunjukkan bahwa skema enkripsi memiliki ketahanan terhadap serangan brute force dan serangan analisis histogram. Citra asli akan memiliki bentuk yang sangat berbeda dengan citra hasil enkripsi yang dibuktikan dengan perhitungan nilai NPCR

The 1995 Science Information Management and Data Compression Workshop

This document is the proceedings from the 'Science Information Management and Data Compression Workshop,' which was held on October 26-27, 1995, at the NASA Goddard Space Flight Center, Greenbelt, Maryland. The Workshop explored promising computational approaches for handling the collection, ingestion, archival, and retrieval of large quantities of data in future Earth and space science missions. It consisted of fourteen presentations covering a range of information management and data compression approaches that are being or have been integrated into actual or prototypical Earth or space science data information systems, or that hold promise for such an application. The Workshop was organized by James C. Tilton and Robert F. Cromp of the NASA Goddard Space Flight Center

Analysis and resynthesis of polyphonic music

This thesis examines applications of Digital Signal Processing to the analysis, transformation, and resynthesis of musical audio. First I give an overview of the human perception of music. I then examine in detail the requirements for a system that can analyse, transcribe, process, and resynthesise monaural polyphonic music. I then describe and compare the possible hardware and software platforms. After this I describe a prototype hybrid system that attempts to carry out these tasks using a method based on additive synthesis. Next I present results from its application to a variety of musical examples, and critically assess its performance and limitations. I then address these issues in the design of a second system based on Gabor wavelets. I conclude by summarising the research and outlining suggestions for future developments

Comparison of CELP speech coder with a wavelet method

This thesis compares the speech quality of Code Excited Linear Predictor (CELP, Federal Standard 1016) speech coder with a new wavelet method to compress speech. The performances of both are compared by performing subjective listening tests. The test signals used are clean signals (i.e. with no background noise), speech signals with room noise and speech signals with artificial noise added. Results indicate that for clean signals and signals with predominantly voiced components the CELP standard performs better than the wavelet method but for signals with room noise the wavelet method performs much better than the CELP. For signals with artificial noise added, the results are mixed depending on the level of artificial noise added with CELP performing better for low level noise added signals and the wavelet method performing better for higher noise levels

Nonlinear approximation with redundant multi-component dictionaries

The problem of efficiently representing and approximating digital data is an open challenge and it is of paramount importance for many applications. This dissertation focuses on the approximation of natural signals as an organized combination of mutually connected elements, preserving and at the same time benefiting from their inherent structure. This is done by decomposing a signal onto a multi-component, redundant collection of functions (dictionary), built by the union of several subdictionaries, each of which is designed to capture a specific behavior of the signal. In this way, instead of representing signals as a superposition of sinusoids or wavelets many alternatives are available. In addition, since dictionaries we are interested in are overcomplete, the decomposition is non-unique. This gives us the possibility of adaptation, choosing among many possible representations the one which best fits our purposes. On the other hand, it also requires more complex approximation techniques whose theoretical decomposition capacity and computational load have to be carefully studied. In general, we aim at representing a signal with few and meaningful components. If we are able to represent a piece of information by using only few elements, it means that such elements can capture its main characteristics, allowing to compact the energy carried by a signal into the smallest number of terms. In such a framework, this work also proposes analysis methods which deal with the goal of considering the a priori information available when decomposing a structured signal. Indeed, a natural signal is not only an array of numbers, but an expression of a physical event about which we usually have a deep knowledge. Therefore, we claim that it is worth exploiting its structure, since it can be advantageous not only in helping the analysis process, but also in making the representation of such information more accessible and meaningful. The study of an adaptive image representation inspired and gave birth to this work. We often refer to images and visual information throughout the course of the dissertation. However, the proposed approximation setting extends to many different kinds of structured data and examples are given involving videos and electrocardiogram signals. An important part of this work is constituted by practical applications: first of all we provide very interesting results for image and video compression. Then, we also face the problem of signal denoising and, finally, promising achievements in the field of source separation are presented