362 research outputs found
Design and FPGA Implementation of High Speed DWT-IDWT Architecture with Pipelined SPIHT Architecture for Image Compression
Image compression demands high speed architectures for transformation and encoding process Medical image compression demands lossless compression schemes and faster architectures A trade-off between speed and area decides the complexity of image compression algorithms In this work a high speed DWT architecture and pipelined SPIHT architecture is designed modeled and implemented on FPGA platform DWT computation is performed using matrix multiplication operation and is implemented on Virtex-5 FPGA that consumes less than 1 of the hardware resource The SPIHT algorithm that is performed using pipelined architecture and hence achieves higher throughput and latency The SPIHT algorithm operates at a frequency of 260 MHz and occupies area less than 15 of the resources The architecture designed is suitable for high speed image compression application
Development of Lifting-based VLSI Architectures for Two-Dimensional Discrete Wavelet Transform
Two-dimensional discrete wavelet transform (2-D DWT) has evolved as an essential
part of a modem compression system. It offers superior compression with good image
quality and overcomes disadvantage of the discrete cosine transform, which suffers
from blocks artifacts that reduces the quality of the inage. The amount of
computations involve in 2-D DWT is enormous and cannot be processed by generalpurpose
processors when real-time processing is required. Th·"efore, high speed and
low power VLSI architecture that computes 2-D DWT effectively is needed. In this
research, several VLSI architectures have been developed that meets real-time
requirements for 2-D DWT applications. This research iaitially started off by
implementing a software simulation program that decorrelates the original image and
reconstructs the original image from the decorrelated image. Then, based on the
information gained from implementing the simulation program, a new approach for
designing lifting-based VLSI architectures for 2-D forward DWT is introduced. As a
result, two high performance VLSI architectures that perform 2-D DWT for 5/3 and
9/7 filters are developed based on overlapped and nonoverlapped scan methods. Then,
the intermediate architecture is developed, which aim a·: reducing the power
consumption of the overlapped areas without using the expensive line buffer. In order
to best meet real-time applications of 2-D DWT with demanding requirements in
terms of speed and throughput parallelism is explored. The single pipelined
intermediate and overlapped architectures are extended to 2-, 3-, and 4-parallel
architectures to achieve speed factors of 2, 3, and 4, respectively. To further
demonstrate the effectiveness of the approach single and para.llel VLSI architectures
for 2-D inverse discrete wavelet transform (2-D IDWT) are developed. Furthermore,
2-D DWT memory architectures, which have been overlooked in the literature, are
also developed. Finally, to show the architectural models developed for 2-D DWT are
simple to control, the control algorithms for 4-parallel architecture based on the first
scan method is developed. To validate architectures develcped in this work five
architectures are implemented and simulated on Altera FPGA.
In compliance with the terms of the Copyright Act 1987 and the IP Policy of the
university, the copyright of this thesis has been reassigned by the author to the legal
entity of the university,
Institute of Technology PETRONAS Sdn bhd.
Due acknowledgement shall always be made of the use of any material contained
in, or derived from, this thesis
Efficient reconfigurable architectures for 3D medical image compression
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Recently, the more widespread use of three-dimensional (3-D) imaging modalities,
such as magnetic resonance imaging (MRI), computed tomography (CT), positron
emission tomography (PET), and ultrasound (US) have generated a massive amount
of volumetric data. These have provided an impetus to the development of other
applications, in particular telemedicine and teleradiology. In these fields, medical
image compression is important since both efficient storage and transmission of data
through high-bandwidth digital communication lines are of crucial importance.
Despite their advantages, most 3-D medical imaging algorithms are computationally intensive with matrix transformation as the most fundamental operation involved in the transform-based methods. Therefore, there is a real need for high-performance systems, whilst keeping architectures exible to allow
for quick upgradeability with real-time applications. Moreover, in order to obtain
efficient solutions for large medical volumes data, an efficient implementation of
these operations is of significant importance. Reconfigurable hardware, in the form of field programmable gate arrays (FPGAs) has been proposed as viable system
building block in the construction of high-performance systems at an economical price.
Consequently, FPGAs seem an ideal candidate to harness and exploit their inherent
advantages such as massive parallelism capabilities, multimillion gate counts, and
special low-power packages. The key achievements of the work presented in this thesis are summarised as follows. Two architectures for 3-D Haar wavelet transform (HWT) have been proposed based on transpose-based computation and partial reconfiguration suitable for 3-D medical imaging applications. These applications require continuous hardware servicing, and as a result dynamic partial reconfiguration (DPR) has been introduced. Comparative study for both non-partial and partial reconfiguration implementation has shown that DPR offers many advantages and leads to a compelling solution for implementing computationally intensive applications such as 3-D medical image compression. Using DPR, several large systems are mapped to small hardware resources, and the area, power consumption as well as maximum frequency are
optimised and improved. Moreover, an FPGA-based architecture of the finite Radon transform (FRAT)with three design strategies has been proposed: direct implementation of pseudo-code with a sequential or pipelined description, and block random access memory (BRAM)- based method. An analysis with various medical imaging modalities has been carried out. Results obtained for image de-noising implementation using FRAT exhibits
promising results in reducing Gaussian white noise in medical images. In terms of
hardware implementation, promising trade-offs on maximum frequency, throughput
and area are also achieved. Furthermore, a novel hardware implementation of 3-D medical image compression system with context-based adaptive variable length coding (CAVLC)
has been proposed. An evaluation of the 3-D integer transform (IT) and the discrete
wavelet transform (DWT) with lifting scheme (LS) for transform blocks reveal that
3-D IT demonstrates better computational complexity than the 3-D DWT, whilst
the 3-D DWT with LS exhibits a lossless compression that is significantly useful for
medical image compression. Additionally, an architecture of CAVLC that is capable
of compressing high-definition (HD) images in real-time without any buffer between
the quantiser and the entropy coder is proposed. Through a judicious parallelisation, promising results have been obtained with limited resources. In summary, this research is tackling the issues of massive 3-D medical volumes data that requires compression as well as hardware implementation to accelerate the
slowest operations in the system. Results obtained also reveal a significant achievement in terms of the architecture efficiency and applications performance.Ministry of Higher Education Malaysia (MOHE),
Universiti Tun Hussein Onn Malaysia (UTHM) and the British Counci
A general framework for efficient FPGA implementation of matrix product
Original article can be found at: http://www.medjcn.com/ Copyright Softmotor LimitedHigh performance systems are required by the developers for fast processing of computationally intensive applications. Reconfigurable hardware devices in the form of Filed-Programmable Gate Arrays (FPGAs) have been proposed as viable system building blocks in the construction of high performance systems at an economical price. Given the importance and the use of matrix algorithms in scientific computing applications, they seem ideal candidates to harness and exploit the advantages offered by FPGAs. In this paper, a system for matrix algorithm cores generation is described. The system provides a catalog of efficient user-customizable cores, designed for FPGA implementation, ranging in three different matrix algorithm categories: (i) matrix operations, (ii) matrix transforms and (iii) matrix decomposition. The generated core can be either a general purpose or a specific application core. The methodology used in the design and implementation of two specific image processing application cores is presented. The first core is a fully pipelined matrix multiplier for colour space conversion based on distributed arithmetic principles while the second one is a parallel floating-point matrix multiplier designed for 3D affine transformations.Peer reviewe
Low power techniques for video compression
This paper gives an overview of low-power techniques proposed in the literature for mobile multimedia and Internet applications. Exploitable aspects are discussed in the behavior of different video compression tools. These power-efficient solutions are then classified by synthesis domain and level of abstraction. As this paper is meant to be a starting point for further research in the area, a lowpower hardware & software co-design methodology is outlined in the end as a possible scenario for video-codec-on-a-chip implementations on future mobile multimedia platforms
A survey of parallel algorithms for fractal image compression
This paper presents a short survey of the key research work that has been undertaken in the application of parallel algorithms for Fractal image compression. The interest in fractal image compression techniques stems from their ability to achieve high compression ratios whilst maintaining a very high quality in the reconstructed image. The main drawback of this compression method is the very high computational cost that is associated with the encoding phase. Consequently, there has been significant interest in exploiting parallel computing architectures in order to speed up this phase, whilst still maintaining the advantageous features of the approach. This paper presents a brief introduction to fractal image compression, including the iterated function system theory upon
which it is based, and then reviews the different techniques that have been, and can be, applied in order to parallelize the compression algorithm
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Efficient architectures and power modelling of multiresolution analysis algorithms on FPGA
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.In the past two decades, there has been huge amount of interest in Multiresolution Analysis Algorithms (MAAs) and their applications. Processing some of their applications such as medical imaging are computationally intensive, power hungry and requires large amount of memory which cause a high demand for efficient algorithm implementation, low power architecture and acceleration. Recently, some MAAs such as Finite Ridgelet Transform (FRIT) Haar Wavelet Transform (HWT) are became very popular and they are suitable for a number of image processing applications such as detection of line singularities and contiguous edges, edge detection (useful for compression and feature detection), medical image denoising and segmentation. Efficient hardware implementation and acceleration of these algorithms particularly when addressing large problems are becoming very chal-lenging and consume lot of power which leads to a number of issues including mobility, reliability concerns. To overcome the computation problems, Field Programmable Gate Arrays (FPGAs) are the technology of choice for accelerating computationally intensive applications due to their high performance. Addressing the power issue requires optimi- sation and awareness at all level of abstractions in the design flow.
The most important achievements of the work presented in this thesis are summarised
here.
Two factorisation methodologies for HWT which are called HWT Factorisation Method1 and (HWTFM1) and HWT Factorasation Method2 (HWTFM2) have been explored to increase number of zeros and reduce hardware resources. In addition, two novel efficient and optimised architectures for proposed methodologies based on Distributed Arithmetic (DA) principles have been proposed. The evaluation of the architectural results have shown that the proposed architectures results have reduced the arithmetics calculation (additions/subtractions) by 33% and 25% respectively compared to direct implementa-tion of HWT and outperformed existing results in place. The proposed HWTFM2 is implemented on advanced and low power FPGA devices using Handel-C language. The FPGAs implementation results have outperformed other existing results in terms of area and maximum frequency. In addition, a novel efficient architecture for Finite Radon Trans-form (FRAT) has also been proposed. The proposed architecture is integrated with the developed HWT architecture to build an optimised architecture for FRIT. Strategies such as parallelism and pipelining have been deployed at the architectural level for efficient im-plementation on different FPGA devices. The proposed FRIT architecture performance has been evaluated and the results outperformed some other existing architecture in place. Both FRAT and FRIT architectures have been implemented on FPGAs using Handel-C language. The evaluation of both architectures have shown that the obtained results out-performed existing results in place by almost 10% in terms of frequency and area. The proposed architectures are also applied on image data (256 £ 256) and their Peak Signal to Noise Ratio (PSNR) is evaluated for quality purposes.
Two architectures for cyclic convolution based on systolic array using parallelism and pipelining which can be used as the main building block for the proposed FRIT architec-ture have been proposed. The first proposed architecture is a linear systolic array with pipelining process and the second architecture is a systolic array with parallel process. The second architecture reduces the number of registers by 42% compare to first architec-ture and both architectures outperformed other existing results in place. The proposed pipelined architecture has been implemented on different FPGA devices with vector size (N) 4,8,16,32 and word-length (W=8). The implementation results have shown a signifi-cant improvement and outperformed other existing results in place.
Ultimately, an in-depth evaluation of a high level power macromodelling technique for design space exploration and characterisation of custom IP cores for FPGAs, called func-tional level power modelling approach have been presented. The mathematical techniques that form the basis of the proposed power modeling has been validated by a range of custom IP cores. The proposed power modelling is scalable, platform independent and compares favorably with existing approaches. A hybrid, top-down design flow paradigm integrating functional level power modelling with commercially available design tools for systematic optimisation of IP cores has also been developed. The in-depth evaluation of this tool enables us to observe the behavior of different custom IP cores in terms of power consumption and accuracy using different design methodologies and arithmetic techniques on virous FPGA platforms. Based on the results achieved, the proposed model accuracy is almost 99% true for all IP core's Dynamic Power (DP) components.Thomas Gerald Gray Charitable Trus
New memory-efficient hardware architecture of 2-D dual-mode lifting-based discrete wavelet transform for JPEG2000
[[abstract]]This work presents new algorithms and hardware architectures to improve the critical issues of the 2-D dual-mode (supporting 5/3 lossless and 9/7 lossy coding) lifting-based discrete wavelet transform (LDWT). The proposed 2-D dual-mode LDWT architecture has the advantages of low-transpose memory, low latency, and regular signal flow, which is suitable for VLSI implementation. The transpose memory requirement of the N ?? N 2-D 5/3 mode LDWT is 2N, and that of 2-D 9/7 mode LDWT is 4N. According to the comparison results, the proposed hardware architecture surpasses previous architectures in the aspects of lifting-based low-transpose memory size. It can be applied to real-time visual operations such as JPEG2000, MPEG-4 still texture object decoding, and wavelet-based scalable video coding.[[notice]]需補會議日期、性質、主辦單位[[conferencedate]]20081119~2008112
Hardware Architecture for the Implementation of the Discrete Wavelet Transform in two Dimensions
Resumen
El artículo presenta una arquitectura hardware que desarrolla la transformada Wavelet en dos dimensiones sobre una
FPGA, en el diseño se buscó un balance entre número de celdas lógicas requeridas y la velocidad de procesamiento.
El artículo inicia con una revisión de trabajos previos, después se presentan los fundamentos teóricos de la
transformación, posteriormente se presenta la arquitectura propuesta seguida por un análisis comparativo. El sistema
se implementó en la FPGA Ciclone II EP2C35F672C6 de Altera utilizando un diseño soportado en el sistema Nios
II. Abstract
This paper presents a hardware architecture developed by the two-dimensional wavelet transform on an FPGA,
in the design it was searched a balance between the number of required logic cells and the processing speed. The
design is based on a methodology to reuse the input data with a parallel-pipelined structure and a calculation of the
coefficients is performed using a method of odd and even numbers, which is achieved by calculating a cycle ratio
after 2 cycles latency, to store the data processing result of the SDRAM memory is used IS42S16400, the control
unit uses a design architecture supported by Nios II processor. The system was implemented in the FPGA Altera
Cyclone II EP2C35F672C6 using a design that combines descriptions in VHDL, schematics and control connection
via a general purpose processor
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