193 research outputs found

    High speed VLSI architectures for DWT in biometric image compression: A study

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    AbstractBiometrics is a field that navigates through a vast database and extracts only the qualifying data to accelerate the processes of biometric authentication/recognition. Image compression is a vital part of the process. Various Very Large Scale Integration (VLSI) architectures have emerged to satisfy the real time requirements of the online processing of the applications. This paper studies various techniques that help in realizing the fast operation of the transform stage of the image compression processes. Various parameters that may involve in optimizations for high speed like computing time, silicon area, memory size etc are considered in the survey

    Discrete Wavelet Transform Core for Image Processing Applications

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    This paper presents a flexible hardware architecture for performing the Discrete Wavelet Transform (DWT) on a digital image. The proposed architecture uses a variation of the lifting scheme technique and provides advantages that include small memory requirements, fixed-point arithmetic implementation, and a small number of arithmetic computations. The DWT core may be used for image processing operations, such as denoising and image compression. For example, the JPEG2000 still image compression standard uses the Cohen-Daubechies-Favreau (CDF) 5/3 and CDF 9/7 DWT for lossless and lossy image compression respectively. Simple wavelet image denoising techniques resulted in improved images up to 27 dB PSNR. The DWT core is modeled using MATLAB and VHDL. The VHDL model is synthesized to a Xilinx FPGA to demonstrate hardware functionality. The CDF 5/3 and CDF 9/7 versions of the DWT are both modeled and used as comparisons. The execution time for performing both DWTs is nearly identical at approximately 14 clock cycles per image pixel for one level of DWT decomposition. The hardware area generated for the CDF 5/3 is around 15,000 gates using only 5% of the Xilinx FPGA hardware area, at 2.185 MHz max clock speed and 24 mW power consumption

    Fast Implementation of Lifting Based DWT Architecture For Image Compression

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    Technological growth in semiconductor industry have led to unprecedented demand for faster area efficient and low power VLSI circuits for complex image processing applications DWT-IDWT is one of the most popular IP that is used for image transformation In this work a high speed low power DWT IDWT architecture is designed and implemented on ASIC using 130nm Technology 2D DWT architecture based on lifting scheme architecture uses multipliers and adders thus consuming power This paper addresses power reduction in multiplier by proposing a modified algorithm for BZFAD multiplier The proposed BZFAD multiplier is 65 faster and occupies 44 less area compared with the generic multipliers The DWT architecture designed based on modified BZFAD multiplier achieves 35 less power reduction and operates at frequency of 200MHz with latency of 1536 clock cycles for 512x512 image The developed DWT can be used as an IP for VLSI implementatio

    Lossless and low-cost integer-based lifting wavelet transform

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    Discrete wavelet transform (DWT) is a powerful tool for analyzing real-time signals, including aperiodic, irregular, noisy, and transient data, because of its capability to explore signals in both the frequency- and time-domain in different resolutions. For this reason, they are used extensively in a wide number of applications in image and signal processing. Despite the wide usage, the implementation of the wavelet transform is usually lossy or computationally complex, and it requires expensive hardware. However, in many applications, such as medical diagnosis, reversible data-hiding, and critical satellite data, lossless implementation of the wavelet transform is desirable. It is also important to have more hardware-friendly implementations due to its recent inclusion in signal processing modules in system-on-chips (SoCs). To address the need, this research work provides a generalized implementation of a wavelet transform using an integer-based lifting method to produce lossless and low-cost architecture while maintaining the performance close to the original wavelets. In order to achieve a general implementation method for all orthogonal and biorthogonal wavelets, the Daubechies wavelet family has been utilized at first since it is one of the most widely used wavelets and based on a systematic method of construction of compact support orthogonal wavelets. Though the first two phases of this work are for Daubechies wavelets, they can be generalized in order to apply to other wavelets as well. Subsequently, some techniques used in the primary works have been adopted and the critical issues for achieving general lossless implementation have solved to propose a general lossless method. The research work presented here can be divided into several phases. In the first phase, low-cost architectures of the Daubechies-4 (D4) and Daubechies-6 (D6) wavelets have been derived by applying the integer-polynomial mapping. A lifting architecture has been used which reduces the cost by a half compared to the conventional convolution-based approach. The application of integer-polynomial mapping (IPM) of the polynomial filter coefficient with a floating-point value further decreases the complexity and reduces the loss in signal reconstruction. Also, the “resource sharing” between lifting steps results in a further reduction in implementation costs and near-lossless data reconstruction. In the second phase, a completely lossless or error-free architecture has been proposed for the Daubechies-8 (D8) wavelet. Several lifting variants have been derived for the same wavelet, the integer mapping has been applied, and the best variant is determined in terms of performance, using entropy and transform coding gain. Then a theory has been derived regarding the impact of scaling steps on the transform coding gain (GT). The approach results in the lowest cost lossless architecture of the D8 in the literature, to the best of our knowledge. The proposed approach may be applied to other orthogonal wavelets, including biorthogonal ones to achieve higher performance. In the final phase, a general algorithm has been proposed to implement the original filter coefficients expressed by a polyphase matrix into a more efficient lifting structure. This is done by using modified factorization, so that the factorized polyphase matrix does not include the lossy scaling step like the conventional lifting method. This general technique has been applied on some widely used orthogonal and biorthogonal wavelets and its advantages have been discussed. Since the discrete wavelet transform is used in a vast number of applications, the proposed algorithms can be utilized in those cases to achieve lossless, low-cost, and hardware-friendly architectures

    Memory-efficient architecture of 2-D dual-mode discrete wavelet transform using lifting scheme for motion-JPEG2000

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    [[abstract]]In this work, we propose a memory-efficient architecture of lifting based two-dimensional discrete wavelet transform (2D DWT) for motion-JPEG2000. The proposed 2D DWT architecture consists of a 1D row processor, internal memory, and a 1D column processor. The main advantage of this 2D DWT is to reduce the internal memory requirement significantly. For an NtimesN image, only 2N and 4N sizes of internal memory are required for the 5/3 and 9/7 filters, respectively, to perform the one-level 2D DWT decomposition. Moreover, it supports both lossless and lossy operation for 5/3 and 9/7 filters with high operation speed. The proposed 2D DWT surpasses the existed lifting-based designs in the aspects of low internal memory requirement. It is suitable for VLSI implementation and can support various real-time image/video applications such as JPEG2000, motion-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]]20090524~2009052

    Diseño hardware de la transformada wavelet discreta: un análisis de complejidad, precisión y frecuencia de operación

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    The purpose of this paper is to present a comparative analysis of hardware design of the Discrete Wavelet Transform (DWT) in terms of three design goals: accuracy, hardware cost and operating frequency. Every design should take into account the following facts: method (non-polyphase, polyphase and lifting), topology (multiplier-based and multiplierless-based), structure (conventional or pipelined), and quantization format (floatingpoint, fixed-point, CSD or integer). Since DWT is widely used in several applications (e.g. compression, filtering, coding, pattern recognition among others), selection of adequate parameters plays an important role in the performance of these systems.El propósito de este documento es presentar un análisis comparativo de esquemas hardware de la Transformada Wavelet Discreta, DWT, en términos de tres objetivos de diseño: precisión, complejidad y frecuencia de operación. Cada diseño debe considerar los siguientes aspectos: método (no polifásico, polifásico y lifting), topología (basados en multiplicadores y sin multiplicadores), estructura (convencional o pipeline) y formato de cuantización (punto flotante, punto fijo, CSD o entero). Dado que la DWT es ampliamente utilizada en diversas aplicaciones (por ejemplo en compresión, filtrado, codificación, reconocimiento de patrones, entre otras), la selección adecuada de parámetros de diseño desempeña un papel importante en el diseño de estos sistemas
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