基于多尺度变换的直觉模糊推理图像融合算法

提出了基于多尺度变换的直觉模糊推理医学图像融合方法,针对4种多尺度变换对图像融合的影响进行了分析。文中融合算法是利用4种多尺度变换对待融合图像进行分解,并对得到的低频分量和高频分量采用直觉模糊推理融合规则进行处理,最后将融合后的低频分量和高频分量经逆变换得到融合图像。实验结果表明本文算法优于传统的模糊推理图像融合算法,并且在变换域中,Contourlet变换下的融合结果要优于其它3种变换。     

Transform-based image enhancement algorithms with performancemeasure

This paper presents a new class of the "frequency domain"-based signal/image enhancement algorithms including magnitude reduction, log-magnitude reduction, iterative magnitude and a log-reduction zonal magnitude technique. These algorithms are described and applied for detection and visualization of objects within an image. The new technique is based on the so-called sequency ordered orthogonal transforms, which include the well-known Fourier, Hartley, cosine, and Hadamard transforms, as well as new enhancement parametric operators. A wide range of image characteristics can be obtained from a single transform, by varying the parameters of the operators. We also introduce a quantifying method to measure signal/image enhancement called EME. This helps choose the best parameters and transform for each enhancement. A number of experimental results are presented to illustrate the performance of the proposed algorithms.     

Multichannel transforms for signal/image processing

This paper presents a novel approach to the Fourier analysis of multichannel time series. Orthogonal matrix functions are introduced and are used in the definition of multichannel Fourier series of continuous-time periodic multichannel functions. Orthogonal transforms are proposed for discrete-time multichannel signals as well. It is proven that the orthogonal matrix functions are related to unitary transforms (e.g., discrete Hartley transform (DHT), Walsh-Hadamard transform), which are used for single-channel signal transformations. The discrete-time one-dimensional multichannel transforms proposed in this paper are related to two-dimensional single-channel transforms, notably to the discrete Fourier transform (DFT) and to the DHT. Therefore, fast algorithms for their computation can be easily constructed. Simulations on the use of discrete multichannel transforms on color image compression have also been performed.     

Fast Algorithm and Low-Cost Hardware-Sharing Design of Multiple Integer Transforms for VC-1

In this brief, the fast 1D multiple integer transforms of Windows Media Video 9 (WMV-9/VC-1) are proposed by matrix decompositions, additions, and row/column permutations. Then, the proposed fast 1D integer transforms are hardware shared, and they can be applied to the 2D transform scheme. The hardware costs of the proposed fast 1D and 2D integer transform designs are smaller than those of the previous individual designs without shares. With the hardware share, the proposed architecture is suitable for the low-cost implementation of the VC-1 codec.     

Pi Coil: A New Element for Bandwidth Extension

This brief presents a new passive element called Pi coil for bandwidth extension. Its transfer function and detailed design tables are given. Based on ideal elements, the proposed Pi coil can achieve the largest bandwidth extension ratio compared to its counterpart, i.e., T coil, and other similar bandwidth-enhancing techniques. In addition, the input return loss (S11) is much improved by using this technique. On-chip implementation methods of the T coil and the Pi coil are also investigated in this brief.     

An Adaptive ELD Compensation Technique Using a Predictive Comparator

This brief presents an adaptive excess loop delay (ELD) compensation technique for continuous-time Delta–Sigma modulators. This technique utilizes a predictive comparator with adaptive control using the sign least-mean-square algorithm to estimate the compensation coefficients. Contrary to other state-of-the-art compensation methods, the proposed technique is immune to manipulation of the loop filter transfer function and loop circuitry. Consequently, it will not deteriorate the performance of the modulators. Simulations performed on two different Delta–Sigma modulators show the effectiveness of the proposed technique to compensate the ELD in low-pass and bandpass Delta–Sigma modulators.      

An inductance enhancement technique and its application to a shunt-peaked 2.5 Gb/s transimpedance amplifier design

This brief presents a bandwidth enhancement technique that is applicable to gigahertz-range broadband circuits. Using the inductance enhancement technique proposed in this brief, a 2.5-Gb/s transimpedance amplifier (TIA) has been implemented based on a 0.35-/spl mu/m CMOS technology. With the input noise reduction, the TIA with the proposed active inductor loads improves the overall system performances including more that 90% increase in bandwidth. Measurements show the bandwidth of 1.73 GHz, transimpedance gain of 68 dB/spl Omega/, and the averaged input referred noise current of 3.3 pA//spl radic/Hz, respectively, while dissipating 50 mW of dc power.     

Wavelet applications in medicine

The author describes how, because of their compatibility with nonstationary random processes, wavelet transforms are particularly powerful when it comes to analyzing biomedical signals. In this paper, he presents a brief survey of the field which makes this fact clear. Applications discussed include detecting coronary artery disease, and heart sounds related to turbulent blood flow analysis     

A Calibrated Phase/Frequency Detector for Reference Spur Reduction in Charge-Pump PLLs

This brief presents a new technique for minimizing reference spurs in a charge-pump phase-locked loop (PLL) while maintaining dead-zone-free operation. The proposed circuitry uses a phase/frequency detector with a variable delay element in its reset path, with the delay length controlled by feedback from the charge-pump. Simulations have been performed with several PLLs to compare the proposed circuitry with previously reported techniques. The proposed approach shows improvements over previously reported techniques of 12 and 16 dB in the two closest reference spurs.     

Stability and Stabilization of Polynomial Fuzzy Systems with Time Delay: New Approach

This paper focuses on the stability and stabilization of polynomial fuzzy systems with time delay. This study is based on a polynomial Lyapunov–Krasovskii functional, and delay-dependent results are described in terms of bilinear sum of squares (SOS) conditions. Two techniques are presented, in this paper, to solve the problem of non-convexity of SOS stability and stabilization conditions for polynomial fuzzy systems with time delay. The first technique presents the SOS stability conditions for a specific class of polynomial fuzzy systems with time delay. Delay-dependent conditions are derived throughout a predefined set of indices. This technique improves delay-independent results existing in the literature. The second method transforms the design problem on an optimization problem subject to SOS constraints. The proposed SOS approach is more innovative and effective than the existing linear matrix inequality in terms of conservatism reduction. The new convex conditions for polynomial fuzzy systems with time delay are shown in terms of SOS which can be solved via SOSTOOLS software. Numerical examples are given to show the effectiveness of the proposed methods.     

Intra-Predictive Transforms for Block-Based Image Coding

This paper presents the theory and the design of intra-predictive transforms, which unify the inter-block prediction and block-based transforms in block-based image coding. Motivated by interpreting inter-block prediction as a transform with a larger size, we derive the concept of intra-predictive transforms. Conventional predictions and transforms can be viewed as special cases of intra-predictive transforms. Intra-predictive transforms are able to exploit both inter and intra-block correlations. We derive the tight upper bound of the coding gain of intra-predictive transforms for stationary Gaussian sources. It turns out that the coding gain can be greater than that of conventional transforms. The optimal intra-predictive transform that achieves the upper bound is also derived. We also design a practical intra-predictive transform using frequency-domain prediction that can achieve better performance in image coding while exhibiting low computational complexity. Experimental results confirm the effectiveness of the proposed intra-predictive transforms in block-based image coding systems and show the improvements over the current design.     

Improving Power-Delay Performance of Ultra-Low-Power Subthreshold SCL Circuits

This brief presents a technique for improving the power-delay performance of subthreshold source-coupled logic (SCL) circuits. Based on the proposed approach, a source-follower buffer stage is used at the output of each SCL stage. Analytical results confirmed by measurements in 0.18-$muhbox{m}$ CMOS technology show an improvement by a factor of as high as 2.4 in power-delay product (PDP). It is also shown that the proposed technique can be used for implementing subthreshold ultra-low power SCL logic gates with a better power and area efficiency, compared to the traditional SCL subthreshold circuits. An optimized approach is proposed to improve the power efficiency of ultra-low power STSCL library cells.      

用于H.264编解码的面向HDTV应用的动态可重构多变换VLSI结构

提出了一种新的支持MPEG-4 AVC/H.264标准4×4整数变换的动态可重构结构.首先,针对4×4正反变换分别推导了两个新的二维直接信号流图.进而设计了一个面向HDTV应用的动态可重构多变换结构.该结构无需转置寄存器且计算单元仅需16个加法器(减法器).采用0.18μm CMOS工艺实现了该电路结构.结果表明,最高...     

Adaptive cascade architectures for image compression

A novel image compression technique is introduced based on adaptive rather than fixed transforms. Fast parameter adaptation allows training to be part of coding. The proposed technique provides higher peak-signal-to-noise ratio than JPEG with a moderate increase in computational complexity, and neural network techniques.     

Robust and secure fractional wavelet image watermarking

This paper presents an efficient fractional wavelet transform (FWT) image watermarking technique based on combining the discrete wavelet transform (DWT) and the fractional Fourier transform (FRFT). In the proposed technique, the host image is wavelet transformed with two resolution levels, and then, the middle frequency sub-bands are FRFT transformed. The watermark is hidden by altering the selected FRFT coefficients of the middle frequency sub-bands of the 2-level DWT-transformed host image. Two pseudo-random noise (PN) sequences are used to modulate the selected FRFT coefficients with the watermark pixels, and inverse transforms are finally applied to get the watermarked image. In watermark extraction, we just need the same two PN sequences used in the embedding process and the watermark size. The correlation factor is used to determine whether the extracted pixel is one or zero. The proposed fractional wavelet transform (FWT) image watermarking method is tested with different image processing attacks and under composite attacks to verify its robustness. Experimental results demonstrated improved robustness and security.     

Statistical feature extraction based technique for fast fractal image compression

Fractal image compression is an innovative way of image representation by using relationships among the sub-section of image itself. It utilizes the existence of self-symmetry and uses affine contractive transforms. This technique has manifold advantages like, very high compression ratio, high decompression speed, high bit-rate and resolution independence, but high computation time expenses of suitable domain search in coding phase is the major bottleneck of the technique. This paper presents a fast fractal compression scheme based on feature extraction and innovative way of image comparison. In proposed development the complexity of suitable domain search is reduced by transforming the problem from image domain to vector domain. Simulation results confirms that suggested variant leads to a faster system as compared to existing state-of art Fractal Image Compression techniques.     

CAVLC Encoder Design for Real-Time Mobile Video Applications

This brief presents a new context-based adaptive variable length coding (CAVLC) architecture. The prototype is designed for the H.264/AVC baseline profile entropy coder. The proposed design offers area savings by reducing the size of the statistic buffer. The arithmetic table elimination technique further reduces the area. The split VLC tables simplify the process of bit-stream generation and also help in reducing some area. The proposed architecture is implemented on Xilinx Virtex II field-programmable gate array (2v3000fg676-4). Simulation result shows that the architecture is capable of processing common/quarter-common intermediate format frame sequences in real-time at a core speed of 50 MHz with 6.85-K logic gates.     

Lyapunov Theory-Based Multilayered Neural Network

This brief presents a Lyapunov theory-based weight adaptation scheme for a multilayered neural network (MLNN) mainly used to classify a multiple-input-multiple-output (MIMO) problem. Initially, the MLNN system is linearized using Taylor series expansion. Then, the weight adaptation scheme is designed based on the Lyapunov stability theory to iteratively update the weight. In the design, the Lyapunov function has to be well selected to construct an energy space with a single global minimum. Hence, the Lyapunov theory-based MLNN acts as a MIMO classifier for face recognition. Analysis and discussion on Lyapunov properties of the proposed classifier are included. The performance of the proposed technique is tested on the Olivetti Research Laboratory database for face classification, and some comparisons with existing conventional techniques are given. Simulation results have revealed that our proposed system achieved better performance.     

数字化伏尔导航接收机的设计

介绍了民用航空飞行中伏尔导航系统（VOR）,在精密进近和着陆中的应用及其性能的比较。针对伏尔导航接收机的不同模式进行结构与性能上的分析,采用当前流行的FPGA等先进数字信号处理技术,提出了不同模式下接收机的硬件实现方案,伏尔导航系统的基本工作原理和相应的方案论证,以及处理过程中一系列适合FPGA实现的新算法、新思路。包括调频、调幅信号的调制解调技术,30Hz可变相与基准相的相位比较技术,数据后处理技术,以及IIR滤波器的性能分析及其FPGA的巧妙实现。     

Energy-Efficient 8-Point DCT Approximations: Theory and Hardware Architectures

Due to its remarkable energy compaction properties, the discrete cosine transform (DCT) is employed in a multitude of compression standards, such as JPEG and H.265/HEVC. Several low-complexity integer approximations for the DCT have been proposed for both 1D and 2D signal analyses. The increasing demand for low-complexity, energy-efficient methods requires algorithms with even lower computational costs. In this paper, new 8-point DCT approximations with very low arithmetic complexity are presented. The new transforms are proposed based on pruning state-of-the-art DCT approximations. The proposed algorithms were assessed in terms of arithmetic complexity, energy retention capability, and image compression performance. In addition, a metric combining performance and computational complexity measures was proposed. Results showed good performance and extremely low computational complexity. Introduced algorithms were mapped into systolic-array digital architectures and physically realized as digital prototype circuits using FPGA technology and mapped to 45 nm CMOS technology. All hardware-related metrics showed low resource consumption of the proposed pruned approximate transforms. The best proposed transform according to the introduced metric presents a reduction in power consumption of 21–25 %.