65 research outputs found

    Efficient data encoder for endoscopic imaging applications

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    The invention of medical imaging technology revolved the process of diagnosing diseases and opened a new world for better studying inside of the human body. In order to capture images from different human organs, different devices have been developed. Gastro-Endoscopy is an example of a medical imaging device which captures images from human gastrointestinal. With the advancement of technology, the issues regarding such devices started to get rectified. For example, with the invention of swallow-able pill photographer which is called Wireless Capsule Endoscopy (WCE); pain, time, and bleeding risk for patients are radically decreased. The development of such technologies and devices has been increased and the demands for instruments providing better performance are grown along the time. In case ofWCE, the special feature requirements such as a small size (as small as an ordinary pill) and wireless transmission of the captured images dictate restrictions in power consumption and area usage. In this research, the reduction of image encoder hardware cost for endoscopic imaging application has been focused. Several encoding algorithms have been studied and the comparative results are discussed. An efficient data encoder based on Lempel-Ziv-Welch (LZW) algorithm is presented. The encoder is a library-based one where the size of library can be modified by the user, and hence, the output data rate can be controlled according to the bandwidth requirement. The simulation is carried out with several endoscopic images and the results show that a minimum compression ratio of 92.5 % can be achieved with a minimum reconstruction quality of 30 dB. The hardware architecture and implementation result in Field-Programmable Gate Array (FPGA) for the proposed window-based LZW are also presented. A new lossy LZW algorithm is proposed and implemented in FPGA which provides promising results for such an application

    Lossless data compression and decompression algorithm and its hardware architecture

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    LZW (Lempel Ziv Welch) and AH (Adaptive Huffman) algorithms were most widely used for lossless data compression. But both of these algorithms take more memory for hardware implementation. The thesis basically discuss about the design of the two-stage hardware architecture with Parallel dictionary LZW algorithm first and Adaptive Huffman algorithm in the next stage. In this architecture, an ordered list instead of the tree based structure is used in the AH algorithm for speeding up the compression data rate. The resulting architecture shows that it not only outperforms the AH algorithm at the cost of only one-fourth the hardware resource but it is also competitive to the performance of LZW algorithm (compress). In addition, both compression and decompression rates of the proposed architecture are greater than those of the AH algorithm even in the case realized by software.Three different schemes of adaptive Huffman algorithm are designed called AHAT, AHFB and AHDB algorithm. Compression ratios are calculated and results are compared with Adaptive Huffman algorithm which is implemented in C language. AHDB algorithm gives good performance compared to AHAT and AHFB algorithms. The performance of the PDLZW algorithm is enhanced by incorporating it with the AH algorithm. The two stage algorithm is discussed to increase compression ratio with PDLZW algorithm in first stage and AHDB in second stage. Results are compared with LZW (compress) and AH algorithm. The percentage of data compression increases more than 5% by cascading with adaptive algorithm, which implies that one can use a smaller dictionary size in the PDLZW algorithm if the memory size is limited and then use the AH algorithm as the second stage to compensate the loss of the percentage of data reduction. The Proposed two–stage compression/decompression processors have been coded using Verilog HDL language, simulated in Xilinx ISE 9.1 and synthesized by Synopsys using design vision

    A novel approach for the hardware implementation of a PPMC statistical data compressor

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    This thesis aims to understand how to design high-performance compression algorithms suitable for hardware implementation and to provide hardware support for an efficient compression algorithm. Lossless data compression techniques have been developed to exploit the available bandwidth of applications in data communications and computer systems by reducing the amount of data they transmit or store. As the amount of data to handle is ever increasing, traditional methods for compressing data become· insufficient. To overcome this problem, more powerful methods have been developed. Among those are the so-called statistical data compression methods that compress data based on their statistics. However, their high complexity and space requirements have prevented their hardware implementation and the full exploitation of their potential benefits. This thesis looks into the feasibility of the hardware implementation of one of these statistical data compression methods by exploring the potential for reorganising and restructuring the method for hardware implementation and investigating ways of achieving efficient and effective designs to achieve an efficient and cost-effective algorithm. [Continues.

    DATA COMPRESSION USING EFFICIENT DICTIONARY SELECTION METHOD

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    With the increase in silicon densities, it is becoming feasible for compression systems to be implemented in chip. A system with distributed memory architecture is based on having data compression and decompression engines working independently on different data at the same time. This data is stored in memory distributed to each processor. The objective of the project is to design a lossless data compression system which operates in high-speed to achieve high compression rate. By using the architecture of compressors, the data compression rates are significantly improved. Also inherent scalability of architecture is possible. The main parts of the system are the data compressors and the control blocks providing control signals for the Data compressors, allowing appropriate control of the routing of data into and from the system. Each Data compressor can process four bytes of data into and from a block of data in every clock cycle. The data entering the system needs to be clocked in at a rate of 4 bytes in every clock cycle. This is to ensure that adequate data is present for all compressors to process rather than being in an idle state

    Analysis of the Performance of IoT Networks in Acoustic Environment by using LZW Data Compression Technique

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    The Internet of Things (IoT) has experienced phenomenal growth, opening up a wide range of applications in many settings. Due to the properties of sound propagation, IoT networks operating in acoustic environments in particular present special difficulties. Data compression techniques can be used to minimize overhead and maximize resource utilization in these networks to increase performance. The performance of IoT networks in acoustic environments is examined in this study, with a focus on routing overhead, throughput, and typical end-to-end delay. Lempel-Ziv-Welch (LZW) data compression is used to reduce data size and boost communication effectiveness. Three well-known protocols—MQTT, CoAP, and Machine-to-Machine (M2M)—are assessed in relation to acoustic Internet of Things networks. To mimic different acoustic conditions and collect performance metrics, a thorough experimental setup is used. Different network topologies, data speeds, and compression settings are used in the studies to determine how they affect the performance metrics. According to the analysis's findings, all three protocols' routing overhead is greatly decreased by the LZW data compression approach, which enhances network scalability and lowers energy usage. Additionally, the compressed data size has a positive impact on network throughput, allowing for effective data transmission in acoustic contexts with limited resources. Additionally, using LZW compression is seen to minimize the average end-to-end delay, improving real-time communication applications. This study advances knowledge of IoT networks operating in acoustic environments and the effects of data reduction methods on their functionality. The results offer useful information for network engineers and system designers to optimize the performance of IoT networks in similar situations. Additionally, a comparison of the MQTT, CoAP, and M2M protocols' suitability for acoustic IoT deployments is provided, assisting in the choice of protocol for particular application needs

    Real-Time Lossless Compression of SoC Trace Data

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    Nowadays, with the increasing complexity of System-on-Chip (SoC), traditional debugging approaches are not enough in multi-core architecture systems. Hardware tracing becomes necessary for performance analysis in these systems. The problem is that the size of collected trace data through hardware-based tracing techniques is usually extremely large due to the increasing complexity of System-on-Chips. Hence on-chip trace compression performed in hardware is needed to reduce the amount of transferred or stored data. In this dissertation, the feasibility of different types of lossless data compression algorithms in hardware implementation are investigated and examined. A lossless data compression algorithm LZ77 is selected, analyzed, and optimized to Nexus traces data. In order to meet the hardware cost and compression performances requirements for the real-time compression, an optimized LZ77 compression algorithm is proposed based on the characteristics of Nexus trace data. This thesis presents a hardware implementation of LZ77 encoder described in Very High Speed Integrated Circuit Hardware Description Language (VHDL). Test results demonstrate that the compression speed can achieve16 bits/clock cycle and the average compression ratio is 1.35 for the minimal hardware cost case, which is a suitable trade-off between the hardware cost and the compression performances effectively

    Optimizing LZW text compression algorithm via multithreading programming

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    Due to the emerging multimedia technology, multimedia files such as text, image, audio and video files are widely used. These multimedia files take hundreds time more space as compared to early day's media files. Thus, demand for efficient compression algorithm is in great needs. Currently, a lot of general purpose multi-core processor machines and systems are widely available. However, many compression algorithms have not been taking advantage of being optimized for these processors. This paper explores the multithreaded compression algorithm to take advantages offered by multi-core processo

    Huffman-based Code Compression Techniques for Embedded Systems

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    Pipeline Task Scheduling on Network Processors

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    Chip Multi-Processors (CMPs) are now available in a variety of systems and provide the opportunity for achieving high computational performance by exploiting application-level parallelism. In the communications environment, network processors (NPs), designed around CMP architectures, are generally usable in a pipelined manner. This leads to the issue of scheduling tasks on processor pipelines. This paper considers problems associated with determining optimal schedules for such pipelines. A system and algorithm called Greedy Pipe is presented. The algorithm employs a greedy heuristic to schedule tasks derived from multiple application flows on pipelines with an arbitrary number of stages. Tasks may be shared, and different bandwidths may be associated with each of the application flows. Experimental results indicate that, 95% of the time Greedy Pipe obtains schedules within 10% of optimal. Examples are given to show the use of Greedy Pipe for general pipeline/algorithm design, and for use in the NP environment with typical networking applications
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