A Lévy Flight Based BAT Optimization Algorithm for Block-based Image Compression

Many metaheuristics have been adopted to solve the codebook generation problem in image processing. In this paper, the Bat algorithm is combined by the Lévy flight distribution to find out the global optimum codebook. The Lévy flight distribution is combined by the local search procedure. Therefore most of the time the bat concentrate on the local area for specific food while it rarely flies to the different parts of the field for better food opportunities. This process strongly guides the bat on the global minimum way and offers better food, then the bat flies to that direction. Consequently, if a bat is captured by a local minimum point accidentally, the Lévy flight step provides a chance to escape from it easily. Numerical results suggest that the proposed Lévy flight based Bat algorithm is better than the classical ones and provides the global optimum codebook for image compression

Computational Optimizations for Machine Learning

The present book contains the 10 articles finally accepted for publication in the Special Issue “Computational Optimizations for Machine Learning” of the MDPI journal Mathematics, which cover a wide range of topics connected to the theory and applications of machine learning, neural networks and artificial intelligence. These topics include, among others, various types of machine learning classes, such as supervised, unsupervised and reinforcement learning, deep neural networks, convolutional neural networks, GANs, decision trees, linear regression, SVM, K-means clustering, Q-learning, temporal difference, deep adversarial networks and more. It is hoped that the book will be interesting and useful to those developing mathematical algorithms and applications in the domain of artificial intelligence and machine learning as well as for those having the appropriate mathematical background and willing to become familiar with recent advances of machine learning computational optimization mathematics, which has nowadays permeated into almost all sectors of human life and activity

Data fusion by using machine learning and computational intelligence techniques for medical image analysis and classification

Data fusion is the process of integrating information from multiple sources to produce specific, comprehensive, unified data about an entity. Data fusion is categorized as low level, feature level and decision level. This research is focused on both investigating and developing feature- and decision-level data fusion for automated image analysis and classification. The common procedure for solving these problems can be described as: 1) process image for region of interest\u27 detection, 2) extract features from the region of interest and 3) create learning model based on the feature data. Image processing techniques were performed using edge detection, a histogram threshold and a color drop algorithm to determine the region of interest. The extracted features were low-level features, including textual, color and symmetrical features. For image analysis and classification, feature- and decision-level data fusion techniques are investigated for model learning using and integrating computational intelligence and machine learning techniques. These techniques include artificial neural networks, evolutionary algorithms, particle swarm optimization, decision tree, clustering algorithms, fuzzy logic inference, and voting algorithms. This work presents both the investigation and development of data fusion techniques for the application areas of dermoscopy skin lesion discrimination, content-based image retrieval, and graphic image type classification --Abstract, page v

Some Intra-Frame and Inter-Frame Processing Schemes for Efficient Video Compression

Rapid increase in digital applications due to recent advances in digital communication and devices needs significant video information storing, processing and transmitting. But the amount of original captured video data is huge and thus makes the system complex in all kind of video processing.But applications demand a faster transmission in different sized electronic devices with good quality.Along with, limited bandwidth and memory for storage makes it challenging. These practical constraints for processing a huge amount of video data, makes video compression as active and challenging field of research. The aim of video compression is to remove redundancy of raw video while maintaining the quality and fidelity. For inter frame processing, motion estimation technique is significantly used to reduce temporal redundancy in almost all the video coding standards e.g. MPEG2, MPEG4, H264/AVC which uses state-of-art algorithm to provide higher compression with a perceptual quality.Though motion estimation is main contributor for higher compression, this is the most computationally complex part of video coding tools. So, it is always a requirement to design an algorithm that is both faster and accurate and provides higher compression but good quality output. The goal of this project is to propose an algorithm for motion estimation which will meet all the requirements and overcome all the practical limitations. In this thesis we analyze the motion of video sequences and some novel block matching based motion estimation algorithms are proposed to improve video coding efficiency in inter frame processing. Particle Swarm Optimization technique and Differential Evolutionary model is used for fast and accurate motion estimation and compensation. Spatial and temporal correlation is adapted for initial population. We followed some strategy for adaptive generations, particle population, particle location history preservation and exploitation. The experimental result shows that our proposed algorithm is efficient to maintain the accuracy. There is significant reduction of search points and thus computational complexity while achieving comparable performance in video coding. Spatial domain redundancy is reduced skipping the irrelevant or spatially co-related data by different sub-sampling algorithm.The sub-sampled intra-frame is up-sampled at the receiver side. The up-sampled high resolution frame requires to have good quality . The existing up-sampling or interpolation techniques produce undesirable blurring and ringing artifacts. To alleviate this problem, a novel spatio-temporal pre-processing approach is proposed to improve the quality. The proposed method use low frequency DCT (Discrete cosine transform) component to sub-sample the frame at the transmitter side. In transmitter side a preprocessing method is proposed where the received subsampled frame is passed through a Wiener filter which uses its local statistics in 3×3 neighborhood to modify pixel values. The output of Wiener filter is added with optimized multiple of high frequency component. The output is then passed through a DCT block to up-sample. Result shows that the proposed method outperforms popularly used interpolation techniques in terms of quality measure

Automatic classification of power quality disturbances using optimal feature selection based algorithm

The development of renewable energy sources and power electronic converters in conventional power systems leads to Power Quality (PQ) disturbances. This research aims at automatic detection and classification of single and multiple PQ disturbances using a novel optimal feature selection based on Discrete Wavelet Transform (DWT) and Artificial Neural Network (ANN). DWT is used for the extraction of useful features, which are used to distinguish among different PQ disturbances by an ANN classifier. The performance of the classifier solely depends on the feature vector used for the training. Therefore, this research is required for the constructive feature selection based classification system. In this study, an Artificial Bee Colony based Probabilistic Neural Network (ABCPNN) algorithm has been proposed for optimal feature selection. The most common types of single PQ disturbances include sag, swell, interruption, harmonics, oscillatory and impulsive transients, flicker, notch and spikes. Moreover, multiple disturbances consisting of combination of two disturbances are also considered. The DWT with multi-resolution analysis has been applied to decompose the PQ disturbance waveforms into detail and approximation coefficients at level eight using Daubechies wavelet family. Various types of statistical parameters of all the detail and approximation coefficients have been analysed for feature extraction, out of which the optimal features have been selected using ABC algorithm. The performance of the proposed algorithm has been analysed with different architectures of ANN such as multilayer perceptron and radial basis function neural network. The PNN has been found to be the most suitable classifier. The proposed algorithm is tested for both PQ disturbances obtained from the parametric equations and typical power distribution system models using MATLAB/Simulink and PSCAD/EMTDC. The PQ disturbances with uniformly distributed noise ranging from 20 to 50 dB have also been analysed. The experimental results show that the proposed ABC-PNN based approach is capable of efficiently eliminating unnecessary features to improve the accuracy and performance of the classifier

A review of clustering techniques and developments

© 2017 Elsevier B.V. This paper presents a comprehensive study on clustering: exiting methods and developments made at various times. Clustering is defined as an unsupervised learning where the objects are grouped on the basis of some similarity inherent among them. There are different methods for clustering the objects such as hierarchical, partitional, grid, density based and model based. The approaches used in these methods are discussed with their respective states of art and applicability. The measures of similarity as well as the evaluation criteria, which are the central components of clustering, are also presented in the paper. The applications of clustering in some fields like image segmentation, object and character recognition and data mining are highlighted

SAR IMAGE COMPRESSION USING ADAPTIVE DIFFERENTIAL EVOLUTION AND PATTERN SEARCH BASED K-MEANS VECTOR QUANTIZATION

A novel Vector Quantization (VQ) technique for encoding the Bi-orthogonal wavelet decomposed image using hybrid Adaptive Differential Evolution (ADE) and a Pattern Search optimization algorithm (hADEPS) is proposed. ADE is a modified version of Differential Evolution (DE) in which mutation operation is made adaptive based on the ascending/descending objective function or fitness value and tested on twelve numerical benchmark functions and the results are compared and proved better than Genetic Algorithm (GA), ordinary DE and FA. ADE is a global optimizer which explore the global search space and PS is local optimizer which exploit a local search space, so ADE is hybridized with PS. In the proposed VQ, in a codebook of codewords, 62.5% of codewords are assigned and optimized for the approximation coefficients and the remaining 37.5% are equally assigned to horizontal, vertical and diagonal coefficients. The superiority of proposed hybrid Adaptive Differential Evolution and Pattern Search (hADE-PS) optimized vector quantization over DE is demonstrated. The proposed technique is compared with DE based VQ and ADE based quantization and with standard LBG algorithm. Results show higher Peak Signal-to-Noise Ratio (PSNR) and Structural Similiraty Index Measure (SSIM) indicating better reconstruction

Soft computing applied to optimization, computer vision and medicine

Artificial intelligence has permeated almost every area of life in modern society, and its significance continues to grow. As a result, in recent years, Soft Computing has emerged as a powerful set of methodologies that propose innovative and robust solutions to a variety of complex problems. Soft Computing methods, because of their broad range of application, have the potential to significantly improve human living conditions. The motivation for the present research emerged from this background and possibility. This research aims to accomplish two main objectives: On the one hand, it endeavors to bridge the gap between Soft Computing techniques and their application to intricate problems. On the other hand, it explores the hypothetical benefits of Soft Computing methodologies as novel effective tools for such problems. This thesis synthesizes the results of extensive research on Soft Computing methods and their applications to optimization, Computer Vision, and medicine. This work is composed of several individual projects, which employ classical and new optimization algorithms. The manuscript presented here intends to provide an overview of the different aspects of Soft Computing methods in order to enable the reader to reach a global understanding of the field. Therefore, this document is assembled as a monograph that summarizes the outcomes of these projects across 12 chapters. The chapters are structured so that they can be read independently. The key focus of this work is the application and design of Soft Computing approaches for solving problems in the following: Block Matching, Pattern Detection, Thresholding, Corner Detection, Template Matching, Circle Detection, Color Segmentation, Leukocyte Detection, and Breast Thermogram Analysis. One of the outcomes presented in this thesis involves the development of two evolutionary approaches for global optimization. These were tested over complex benchmark datasets and showed promising results, thus opening the debate for future applications. Moreover, the applications for Computer Vision and medicine presented in this work have highlighted the utility of different Soft Computing methodologies in the solution of problems in such subjects. A milestone in this area is the translation of the Computer Vision and medical issues into optimization problems. Additionally, this work also strives to provide tools for combating public health issues by expanding the concepts to automated detection and diagnosis aid for pathologies such as Leukemia and breast cancer. The application of Soft Computing techniques in this field has attracted great interest worldwide due to the exponential growth of these diseases. Lastly, the use of Fuzzy Logic, Artificial Neural Networks, and Expert Systems in many everyday domestic appliances, such as washing machines, cookers, and refrigerators is now a reality. Many other industrial and commercial applications of Soft Computing have also been integrated into everyday use, and this is expected to increase within the next decade. Therefore, the research conducted here contributes an important piece for expanding these developments. The applications presented in this work are intended to serve as technological tools that can then be used in the development of new devices

Metaheuristic design of feedforward neural networks: a review of two decades of research

Over the past two decades, the feedforward neural network (FNN) optimization has been a key interest among the researchers and practitioners of multiple disciplines. The FNN optimization is often viewed from the various perspectives: the optimization of weights, network architecture, activation nodes, learning parameters, learning environment, etc. Researchers adopted such different viewpoints mainly to improve the FNN's generalization ability. The gradient-descent algorithm such as backpropagation has been widely applied to optimize the FNNs. Its success is evident from the FNN's application to numerous real-world problems. However, due to the limitations of the gradient-based optimization methods, the metaheuristic algorithms including the evolutionary algorithms, swarm intelligence, etc., are still being widely explored by the researchers aiming to obtain generalized FNN for a given problem. This article attempts to summarize a broad spectrum of FNN optimization methodologies including conventional and metaheuristic approaches. This article also tries to connect various research directions emerged out of the FNN optimization practices, such as evolving neural network (NN), cooperative coevolution NN, complex-valued NN, deep learning, extreme learning machine, quantum NN, etc. Additionally, it provides interesting research challenges for future research to cope-up with the present information processing era

Fast and Efficient Foveated Video Compression Schemes for H.264/AVC Platform

Some fast and efficient foveated video compression schemes for H.264/AVC platform are presented in this dissertation. The exponential growth in networking technologies and widespread use of video content based multimedia information over internet for mass communication applications like social networking, e-commerce and education have promoted the development of video coding to a great extent. Recently, foveated imaging based image or video compression schemes are in high demand, as they not only match with the perception of human visual system (HVS), but also yield higher compression ratio. The important or salient regions are compressed with higher visual quality while the non-salient regions are compressed with higher compression ratio. From amongst the foveated video compression developments during the last few years, it is observed that saliency detection based foveated schemes are the keen areas of intense research. Keeping this in mind, we propose two multi-scale saliency detection schemes. (1) Multi-scale phase spectrum based saliency detection (FTPBSD); (2) Sign-DCT multi-scale pseudo-phase spectrum based saliency detection (SDCTPBSD). In FTPBSD scheme, a saliency map is determined using phase spectrum of a given image/video with unity magnitude spectrum. On the other hand, the proposed SDCTPBSD method uses sign information of discrete cosine transform (DCT) also known as sign-DCT (SDCT). It resembles the response of receptive field neurons of HVS. A bottom-up spatio-temporal saliency map is obtained by linear weighted sum of spatial saliency map and temporal saliency map. Based on these saliency detection techniques, foveated video compression (FVC) schemes (FVC-FTPBSD and FVC-SDCTPBSD) are developed to improve the compression performance further.Moreover, the 2D-discrete cosine transform (2D-DCT) is widely used in various video coding standards for block based transformation of spatial data. However, for directional featured blocks, 2D-DCT offers sub-optimal performance and may not able to efficiently represent video data with fewer coefficients that deteriorates compression ratio. Various directional transform schemes are proposed in literature for efficiently encoding such directional featured blocks. However, it is observed that these directional transform schemes suffer from many issues like ‘mean weighting defect’, use of a large number of DCTs and a number of scanning patterns. We propose a directional transform scheme based on direction-adaptive fixed length discrete cosine transform (DAFL-DCT) for intra-, and inter-frame to achieve higher coding efficiency in case of directional featured blocks.Furthermore, the proposed DAFL-DCT has the following two encoding modes. (1) Direction-adaptive fixed length ― high efficiency (DAFL-HE) mode for higher compression performance; (2) Direction-adaptive fixed length ― low complexity (DAFL-LC) mode for low complexity with a fair compression ratio. On the other hand, motion estimation (ME) exploits temporal correlation between video frames and yields significant improvement in compression ratio while sustaining high visual quality in video coding. Block-matching motion estimation (BMME) is the most popular approach due to its simplicity and efficiency. However, the real-world video sequences may contain slow, medium and/or fast motion activities. Further, a single search pattern does not prove efficient in finding best matched block for all motion types. In addition, it is observed that most of the BMME schemes are based on uni-modal error surface. Nevertheless, real-world video sequences may exhibit a large number of local minima available within a search window and thus possess multi-modal error surface (MES). Hence, the following two uni-modal error surface based and multi-modal error surface based motion estimation schemes are developed. (1) Direction-adaptive motion estimation (DAME) scheme; (2) Pattern-based modified particle swarm optimization motion estimation (PMPSO-ME) scheme. Subsequently, various fast and efficient foveated video compression schemes are developed with combination of these schemes to improve the video coding performance further while maintaining high visual quality to salient regions. All schemes are incorporated into the H.264/AVC video coding platform. Various experiments have been carried out on H.264/AVC joint model reference software (version JM 18.6). Computing various benchmark metrics, the proposed schemes are compared with other existing competitive schemes in terms of rate-distortion curves, Bjontegaard metrics (BD-PSNR, BD-SSIM and BD-bitrate), encoding time, number of search points and subjective evaluation to derive an overall conclusion