Tinku Acharya

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Dr. Tinku Acharya is an inventor, entrepreneur, scientist, teacher, author, and an internationally acclaimed technologist. He received his B.Sc. (Honors in Physics), B. Tech and M. Tech in Computer Science from University of Calcutta, and PhD in Computer Science from University of Central Florida, USA. He is a Fellow of IEEE, INAE, IETE, and other institutions. Dr. Acharya is an inventor of 167 patents in various technology domains - visual computing architectures, electronic imaging, data compression, multimedia computing, computer vision, intelligent video, VLSI architectures and algorithms, etc. He contributed to over 100 technical papers and author of 4 books - (i) Image Processing: Principles and Applications (Wiley, USA, 2005), (ii) JPEG2000 Standard for Image Compression: Concepts, Algorithms, and VLSI Architectures (Wiley, USA 2004), (iii) Information Technology: Principles and Applications (Prentice-Hall India, 2004), and (iv) Data Mining: Multimedia, Soft Computing and Bioinformatics (Wiley, USA, 2003).

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Remotely Sensed Multispectral Scene Analysis

John Wiley & Sons, Inc. eBooks, Sep 20, 2005

Image Enhancement and Restoration

John Wiley & Sons, Inc. eBooks, Sep 20, 2005

Recognition of Image Patterns

Discrete Wavelet Transform

Article Outline Glossary 1 1. Definition 8 2. Introduction 8 3. The discrete vs continuous wavele... more Article Outline Glossary 1 1. Definition 8 2. Introduction 8 3. The discrete vs continuous wavelet Algorithms 9 3.1. The Discrete Wavelet Transform 9 3.2. The Continuous Wavelet Transform 11 3.3. Some background on Hilbert space 11 3.4. Connections to group theory 15 4. List of names and discoveries 16 5. History 18 6. Tools from Mathematics 19 7. A Transfer Operator 20 8. Future Directions 20 9. Literature 21 10. Bibliography 21 21 Glossary This glossary consists of a list of terms used inside the paper: In mathematics, in probability, in engineering, and on occasion in physics. To clarify the seemingly confusing use of up to four different names for the same idea or concept, we have further added informal explanations spelling out the reasons behind the differences in current terminology from neighboring fields. Disclaimer: This glossary has the structure of four columns. A number of terms are listed line by line, and each line is followed by explanation. Some "terms" have up to four separate (yet commonly accepted) names. mathematics probability engineering physics function (measurable) random variable signal state Mathematically, functions may map between any two sets, say, from X to Y ; but if X is a probability space (typically called Ω),

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Digital watermarking using homogeneity in image

A new technique of digital watermarking for graylevel images is reported in this paper. Digital w... more A new technique of digital watermarking for graylevel images is reported in this paper. Digital watermarking/hiding has emerged as a new area of research in connection to Intellectual Property (IP) protection of images. The redundancy in image representation can be exploited successfully to hide some characteristic information in images, without noticeable distortion. Hidden information after extraction, can be used to protect copyright. This article deals with a block-based technique for inserting a copyright mark (invisible logo) into a gray-level image. The robustness of the proposed method has been tested against non-destructive attacks like mean and median filtering.

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Image processing

Memory efficient progressive rate-distortion algorithm for JPEG 2000

IEEE Transactions on Circuits and Systems for Video Technology, 2005

A novel rate-distortion optimization algorithm for JPEG 2000 is proposed. In JPEG 2000 standard, ... more A novel rate-distortion optimization algorithm for JPEG 2000 is proposed. In JPEG 2000 standard, the encoder generates a number of independent compressed bit streams. But it is the rate-control algorithm that generates truncation points for these bit streams in an optimal way in order to minimize the distortion according to a target bit rate. In this letter, we propose a computationally efficient rate-distortion optimization algorithm that generates the truncation points of the compressed bit streams during the encoding procedure to avoid unnecessary coding of the possible discarded bit streams for the given bit rate. This algorithm meets memory buffer requirement for the compressed bit streams quite strictly according to a given bit rate. Moreover, before the encoding process even starts, a required memory buffer size can be estimated. This algorithm can also help avoid unnecessary encoding for some parts of an image. Hence, it is memory efficient and supports progressive encoding also. In low bit rate application the proposed algorithm can greatly reduce the encoder complexity and buffer requirement.

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A VLSI architecture for lifting-based wavelet transform

The discrete wavelet transform (DWT) is the basis for many image compression techniques, such as ... more The discrete wavelet transform (DWT) is the basis for many image compression techniques, such as the upcoming JEPG2000. Lifting-based DWT requires fewer computations compared to the traditional convolution-based approach. In this paper, we propose a VLSI architecture to compute lifting-based 2D DWT, for a set of seven filters recommended in the JPEG2000 verification model. The architecture produces transform coefficients in every clock cycle for three of the filters and in every alternate cycle for the rest of the filters. We also present an efficient memory organization to address the high memory bandwidth requirements. The performance metrics of the proposed architecture have also been furnished

Biometric and Biomedical Image Processing

VLSI Architectures for Discrete Wavelet Transforms

John Wiley & Sons, Inc. eBooks, Jan 28, 2005

This paper presents two classes of novel VLSI architectures, referred to as the folded architectu... more This paper presents two classes of novel VLSI architectures, referred to as the folded architecture and the digit-serial architecture, for implementation of one-and two-dimensional discrete wavelet transforms. In the one-dimensional folded architecture, the computations of all wavelet levels are folded to the same low-pass and high-pass filters. The number of registers in the folded architecture is minimized by the use of a generalized life time analysis. The converter units are synthesized with minimum number of registers using forward-backward allocation. The advantage of the folded architecture is low latency and its drawbacks are increased hardware area, less than 100% hardware utilization, and complex routing and interconnection required by the converters used in this architecture. These drawbacks are eliminated in the alternate digit-serial architecture which requires simpler control circuits, routing, and interconnection, achieves complete hardware utilization, and requires lower power, at the expense of an increase in the system latency and some constraints on the wordlength. In latency-critical applications, we propose the use of the folded architecture. If latency is not so critical, we propose the use of the digit-serial architecture. The use of a combined folded and digit-serial architecture is proposed for implementation of two-dimensional discrete wavelet transforms.

format_quoteOnly two filters are necessary for the maximum number of filters needed for one-dimensional wavelet computation.format_quote

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Hardware Architecture for Ridge Extraction in Fingerprints: A Combinatorial Approach

WORLD SCIENTIFIC eBooks, May 1, 2008

ABSTRACT

Color and Color Imagery

New Computationally Efficient Algorithms for Video Coding

Series in machine perception and artificial intelligence, Nov 1, 2002

Dynamic Scene Analysis: Moving Object Detection and Tracking

John Wiley & Sons, Inc. eBooks, Sep 20, 2005

US Patent Pending

Zerotree coding is an intelligent approach for quantization of Discrete Wavelet coefficients and ... more Zerotree coding is an intelligent approach for quantization of Discrete Wavelet coefficients and thus achieving image compression. Embedded Zerotree Coding by Shapiro [3] is very effective in this regard, having the property that the bits in the bit stream are generated in order of importance, yielding a fully embedded code. In this paper we have proposed a Modified Embedded Zerotree (MEZT) scheme which is computationally more efficient, making it more suitable for real time video compression applications. MEZT is a bit plane wise single pass algorithm, unlike Shapiro's two pass technique. This leads to reduction in processing time. Depending on the priority of bit budget or compression ratio, the number of bit planes to be encoded can be decided. More over, since most of the necessary tasks are bit operations, it is more suitable for VLSI implementation.

Image Processing: Principles and Applications

Journal of Electronic Imaging, Jul 1, 2006

Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best ef... more Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

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VLSI algorithms and architectures for data compression

Despite the fact that the memory cost has decreased drastically over the past few years, the data... more Despite the fact that the memory cost has decreased drastically over the past few years, the data storage requirements and data processing applications are growing explosively. Data compression methods are used to reduce the redundancy in data representation in order to decrease the storage requirements and communication costs. To take advantage of the VLSI technology, application-specific hardware algorithms and architectures for real-time systems with data parallelism would have to be developed as standard components for communication and storage. In this dissertation, we develop a new memory-based architecture for multibit encoding and decoding of Huffman-type tree-based codes such that multiple number of bits can be encoded or decoded in one clock cycle. We present simulation results that lead to the design and implementation of a memory-based VLSI CODEC architecture. We also develop new parallel algorithms for image decorrelation schemes and present the design of a VLSI chip wh...

A DWT-based perceptually lossless color image compression architecture

Asilomar Conference on Signals, Systems & Computers, 1998

In this paper we propose a DWT-based perceptually lossless image compression algorithm and archit... more In this paper we propose a DWT-based perceptually lossless image compression algorithm and architecture. Many image-capturing devices acquire images in subsampled R-G-B format and have real-time constraints which prohibit conversion to other formats, generally preferred for image compression, such as Y-Cb-Cr. Therefore, we propose a compression algorithm which works performed directly on the subsampled R-G-B data. The scheme exploits the

Multiplierless pyramid filter

A New Probabilistic Approach for Fractal Based Image Compression

Approximation of an image by the attractor evolved through iterations of a set of contractive map... more Approximation of an image by the attractor evolved through iterations of a set of contractive maps is usually known as fractal image compression. The set of maps is called iterated function system (IFS). Several algorithms, with different motivations, have been suggested towards the solution of this problem. But, so far, the theory of IFS with probabilities, in the context of image compression, has not been explored much. In the present article we have proposed a new technique of fractal image compression using the theory of IFS and probabilities. In our proposed algorithm, we have used a multiscaling division of the given image up to a predetermined level or up to that level at which no further division is required. At each level, the maps and the corresponding probabilities are computed using the gray value information contained in that image level and in the image level higher to that level. A fine tuning of the algorithm is still to be done. But, the most interesting part of the proposed technique is its extreme fastness in image encoding. It can be looked upon as one of the solutions to the problem of huge computational cost for obtaining fractal code of images.

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Tinku Acharya

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