84 research outputs found

    Analysis of runtime re-configuration systems

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    In recent years Programmable Logic Devices (PLD) and in particular Field Programmable Gate Arrays (FPGAs) have seen a tremendous increase in sales and applications in the area of embedded systems. The main advantage of FPGAs is the flexibility that they offer a designer in reconfiguring the hardware. The flexibility achieved through re-configuration of FPGAs usually incurs an overhead of extra execution time, data memory and also power dissipation; FPGAs provide an ideal template for run-time reconfigurable (RTR) designs. Only recently have RTR enabling design tools that bypass the traditional synthesis and bitstream generation process for FPGAs become available, JBits is one of them. With run-time reconfiguration of FPGAs, we can perform partial reconfiguration, which allows reconfiguration of a part of an FPGA while the other part is executing some functional computation. The partial reconfiguration of a function can be performed earlier than the time when the function is really needed. Such configuration pre-fetch can hide the reconfiguration overhead more effectively; This thesis will implement a reconfigurable system and study the effect of runtime reconfiguration using VERILOG and a new Java based tool JBITS. This work will provide pointers to high level synthesis tools targeting runtime re-configuration

    An Energy Efficient and High Speed Image Compression System Using Stationary Wavelet Transform

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    Image compression is one of the interesting domains nowadays in all areas of research. Everybody working with huge of amount of data in their daily life. In-order to deal with such huge amount of data, there is a need to store and compress the data. So there is a need to develop a system to compress and store the data. JPEG 2000 is a system to achieve this object. In this paper an area efficient and high speed JPEG2000 architecture has been developed to compress the image data. To implement JPEG2000 system, here a transform called stationary wavelet transform has been used. Stationary wavelet transform reduces the bottlenecks existing in the wavelet transform. Stationary wavelet transform avoids the problem of invariance-translation of the already existing discrete wavelet transform. The proposed stationary wavelet transform based JPEG2000 improves the speed and efficiency of power compared to the discrete wavelet transform based JPEG2000. Many image compression applications such as tele-medicine, satellite imaging, medical imaging require high-speed, low power compression techniques with small chip area. This paper has an analysis on the speed of JPEG2000 using stationary wavelet transform and it will be compared theoretically and practically with the JPEG2000 using discrete wavelet transform. The amount of information missing in the test image usually been very small when compared to the DWT based JPEG2000.The MSE and PSNR values proved to be better when compared to the DWT based JPEG2000. The proposed SWT based JPEG2000 compresses and decompresses the image at a faster rate than the DWT based JPEG2000.Finally the design will be implemented in XILINX Virtex-4 FPGA Kit. .The power consumption of the proposed method proved to be 290mW compared to other types of compression techniques

    Remote Sensing Data Compression

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    A huge amount of data is acquired nowadays by different remote sensing systems installed on satellites, aircrafts, and UAV. The acquired data then have to be transferred to image processing centres, stored and/or delivered to customers. In restricted scenarios, data compression is strongly desired or necessary. A wide diversity of coding methods can be used, depending on the requirements and their priority. In addition, the types and properties of images differ a lot, thus, practical implementation aspects have to be taken into account. The Special Issue paper collection taken as basis of this book touches on all of the aforementioned items to some degree, giving the reader an opportunity to learn about recent developments and research directions in the field of image compression. In particular, lossless and near-lossless compression of multi- and hyperspectral images still remains current, since such images constitute data arrays that are of extremely large size with rich information that can be retrieved from them for various applications. Another important aspect is the impact of lossless compression on image classification and segmentation, where a reasonable compromise between the characteristics of compression and the final tasks of data processing has to be achieved. The problems of data transition from UAV-based acquisition platforms, as well as the use of FPGA and neural networks, have become very important. Finally, attempts to apply compressive sensing approaches in remote sensing image processing with positive outcomes are observed. We hope that readers will find our book useful and interestin

    Técnicas de compresión de imágenes hiperespectrales sobre hardware reconfigurable

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    Tesis de la Universidad Complutense de Madrid, Facultad de Informática, leída el 18-12-2020Sensors are nowadays in all aspects of human life. When possible, sensors are used remotely. This is less intrusive, avoids interferces in the measuring process, and more convenient for the scientist. One of the most recurrent concerns in the last decades has been sustainability of the planet, and how the changes it is facing can be monitored. Remote sensing of the earth has seen an explosion in activity, with satellites now being launched on a weekly basis to perform remote analysis of the earth, and planes surveying vast areas for closer analysis...Los sensores aparecen hoy en día en todos los aspectos de nuestra vida. Cuando es posible, de manera remota. Esto es menos intrusivo, evita interferencias en el proceso de medida, y además facilita el trabajo científico. Una de las preocupaciones recurrentes en las últimas décadas ha sido la sotenibilidad del planeta, y cómo menitoirzar los cambios a los que se enfrenta. Los estudios remotos de la tierra han visto un gran crecimiento, con satélites lanzados semanalmente para analizar la superficie, y aviones sobrevolando grades áreas para análisis más precisos...Fac. de InformáticaTRUEunpu

    An efficient H.264 intra frame coder hardware design

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    H.264 / MPEG-4 Part 10, a recently developed international standard for video compression, offers significantly better video compression efficiency than previous international standards. Since it is impossible to implement a real-time H.264 video coder using a state-of-the-art embedded processor alone, in this thesis, we developed an efficient FPGA-based H.264 intra frame coder hardware for real-time portable applications targeting level 2.0 of baseline profile. We first designed a high performance and low cost hardware architecture for realtime implementation of entropy coding algorithms, context adaptive variable length coding and exp-golomb coding, used in H.264 video coding standard. The hardware is implemented in Verilog HDL and verified with RTL simulations using Mentor Graphics Modelsim. We then designed a high performance and low cost hardware architecture for real-time implementation of intra prediction algorithm used in H.264 video coding standard. This hardware is also implemented in Verilog HDL and verified with RTL simulations using Mentor Graphics Modelsim. We then designed and implemented the top-level H.264 intra frame coder hardware. The hardware is implemented by integrating intra prediction, mode decision, transform-quant and entropy coding modules. The H.264 intra frame coder hardware is verified to be compliant with H.264 standard and it can code 35 CIF (352x288) frames per second. The hardware is first verified with RTL simulations using Mentor Graphics Modelsim. It is then verified to work at 71 MHz on a Xilinx Virtex II FPGA on an ARM Versatile Platform development board. The bitstream generated by the H.264 intra frame coder hardware for an input frame is successfully decoded by H.264 Joint Model (JM) reference software decoder and the decoded frame is displayed using a YUV Player tool for visual verification

    Development Of Efficient Multi-Level Discrete Wavelet Transform Hardware Architecture For Image Compression

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    Berfokuskan pengkomputeran intensif dalam gelombang kecil diskret (DWT), reka bentuk seni bina perkakasan efisen bagi pengkomputeran laju menjadi imperatif terutamanya dalam aplikasi masa nyata. Focusing on the intensive computations involved in the discrete wavelet transform (DWT), the design of efficient hardware architectures for a fast computation of the transform has become imperative, especially for real-time applications

    LOCO-ANS: An Optimization of JPEG-LS Using an Efficient and Low-Complexity Coder Based on ANS

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    Near-lossless compression is a generalization of lossless compression, where the codec user is able to set the maximum absolute difference (the error tolerance) between the values of an original pixel and the decoded one. This enables higher compression ratios, while still allowing the control of the bounds of the quantization errors in the space domain. This feature makes them attractive for applications where a high degree of certainty is required. The JPEG-LS lossless and near-lossless image compression standard combines a good compression ratio with a low computational complexity, which makes it very suitable for scenarios with strong restrictions, common in embedded systems. However, our analysis shows great coding efficiency improvement potential, especially for lower entropy distributions, more common in near-lossless. In this work, we propose enhancements to the JPEG-LS standard, aimed at improving its coding efficiency at a low computational overhead, particularly for hardware implementations. The main contribution is a low complexity and efficient coder, based on Tabled Asymmetric Numeral Systems (tANS), well suited for a wide range of entropy sources and with simple hardware implementation. This coder enables further optimizations, resulting in great compression ratio improvements. When targeting photographic images, the proposed system is capable of achieving, in mean, 1.6%, 6%, and 37.6% better compression for error tolerances of 0, 1, and 10, respectively. Additional improvements are achieved increasing the context size and image tiling, obtaining 2.3% lower bpp for lossless compression. Our results also show that our proposal compares favorably against state-of-the-art codecs like JPEG-XL and WebP, particularly in near-lossless, where it achieves higher compression ratios with a faster coding speedThis work was supported in part by the Spanish Research Agency through the Project AgileMon under Grant AEI PID2019-104451RB-C2

    Towards wireless sensor networks with enhanced vision capabilities

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    Wireless sensor networks are expected to become an important tool for various security, surveillance and/or monitoring applications. The paper discusses selected practical aspects of development of such networks. First, design and implementation of an exemplary wireless sensor network for intrusion detection and classification are briefly presented. The network consists of two levels of nodes. At the first level, relatively simple microcontroller-based nodes with basic sensing devices and wireless transmission capabilities are used. These nodes are used as preliminary detectors of prospective intrusions. The second-level sensor node is built around a high performance FPGA controlling an array of cameras. The second-level nodes can be dynamically reconfigured to perform various types of visual data processing and analysis algorithms used to confirm the presence of intruders in the scene and to classify approximately the intrusion, if any. The paper briefly presents algorithms and overviews hardware of the network. In the last part of the paper, prospective directions for wireless sensor networks are analyzed and certain recommendations are included
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