A NEW EDGE DETECTOR WITH THINNING AND NOISE RESISTING ABILITIES

This paper presents a new edge detector using 5 ~ 5 mask, which can reduce noise efficientlybut not increase the width of the detected edge which always happens in the case of using the 5×5 windowedge detector. Besides, in order to handle the problem that the contrast decreases in the dark regioncaused by underexposure, this detector uses a self-adjusting threshold, so that it can detect the edge in re-gions of different grey background correctly.     

快速高效去除图像椒盐噪声的均值滤波算法

针对常见滤除椒盐噪声算法需要使用阈值、运算时间长、去除噪声效果不理想等缺陷,提出了一种快速高效去除图像椒盐噪声的均值滤波算法。新算法对滤波窗口下的疑似噪声像素,有针对性地选择少数信号像素构成信号像素集合,取集合中的元素均值对疑似噪声像素进行滤波。实验结果表明,对于噪声密度为1%到99%的图像,新算法均具有良好的去除噪声能力和保持细节能力,而且整个算法耗费时间很少,因而具有较大的实用性。     

异构环境下网格计算模式及体系结构研究

网格计算模式具有机群系统不可比拟的优势,它可以更好地解决资源的异构性问题,支持资源的柔性伸缩及多种并行编程环境,支持科学计算库与工具软件,支持可视化动态人机交互.网格计算模式的体系结构是具有一定智能的分层结构.参考五层沙漏结构思想和前人的研究成果,研究设计了具有资源底层、安全调度层、抽象接口层、中间件层、应用接口层和应用层等六个层面的网格计算系统多层体系结构.     

Enhanced multi-level filter algorithm and its VLSI architecture

This paper presents an enhanced multi-level filter algorithm and its Very Large Scale Integration (VLSI) architecture for infrared image processing. The modified multi-level filter algorithm resolves the splitting targets problem using Gaussian pyramid processing. Owning three filtering paths, the proposed VLSI architecture of the filter can simultaneously enhance small targets with different sizes in infrared images. Some design techniques in implementing hardwired multiplication, subsample and asynchronous FIFO have been presented. This VLSI architecture has been implemented using Semiconductor Manufacturing International Corporation (SMIC) 0.35?µm 4-layer CMOS technology. The simulation results show that it not only effectively suppresses background, eliminates noise and enhances small targets in an infrared image comparing with other small target detective methods, but also meets infrared image real-time processing requirements (5?M?～?10?M pixels/s). The implemented filter chip consists of 60,284 gates and 8?K Static Random Access Memory (SRAM), operates at 50?MHz.     

基于加权网络和OWA算子的图像椒盐噪声滤除算法

用加权网络对图像进行建模,可以有效地表示图像的结构特征,其中网络单个节点的点强度集成了节点本身与其它点连接的边数和强度信息。为了发挥结构信息和统计信息在图像分析中的作用,用加权网络对图像进行表示。根据噪声像素与周围像素差异性大的特点,将噪声检测问题转化为搜索网络中具有最小点强度的节点问题。采用有序加权平均（OWA）算子...     

Unsupervised image thresholding: hardware architecture and its usage for FPGA-SoC platform

ABSTRACT

Otsu’s global automatic image thresholding operation is used in various image processing applications. It needs computation of normalized cumulative histogram, mean and cumulative moments that are compute-intensive operations. In this paper, a custom architecture is presented for an efficient computation of Otsu’s algorithm along with its utilization as an intellectual property (IP) core in a field programmable gate array (FPGA) based system-on-chip (SoC) environment for the application of connected component analysis (CCA). A self-normalization technique is employed, where single-cycle, read–modify–write operations are performed with block random access memories (BRAMs) and digital signal processing (DSP)slices. The architecture is designed for 640 × 480 size of images that are captured by a high-resolution analouge camera and buffered in a DDR2 SDRAM of Xilinx ML-507 platform at 25.175 MHz clock frequency. The embedded PowerPC processor core is used to control the frame acquisition process. Experimental results on Virtex-5 xc5vfx70t FPGA device show that the architecture utilizes 1.4% slices, 2.7% BRAMs and 3.9% DSP48E slices. The total power consumption of the design is 1440.59 mW. The proposed architecture as an IP core is able to work in real-time with standard VGA resolution video and requires low computational resources.     

Nonlinear order statistic filters for image filtering and edge detection

A novel class of nonlinear filters for image processing is proposed. This class is a combination of nonlinear mean and order statistic filters. Median, homomorphic, α-trimmed mean, nonlinear mean, order statistic, and linear filters can be considered as special cases of this class. The properties of these filters in the presence of different kinds of noise are investigated. It is shown that these filters can be used for the reduction of additive white noise, signal-dependent noise, and impulse noise. It is also shown that they preserve edges better than linear filters. Such filters can successfully be used as edge detectors, by appropriate adjustment of some of their parameters. Edge information can be used as an input to these filters to perform in an adaptive manner, changing their behaviour near the edges of an image. It is finally shown that many of the filters proposed have a reasonable (and in certain cases small) computational complexity.     

数据链网络信息融合的有中心无中心处理结构

针对数据链网络的发展趋势及应用需求,揭示了有中心无中心融合处理的基本原理,并对其处理流程与关键技术进行了深入分析,并提供了解决思路及仿真分析。在此基础上,结合机载信息融合的功能及应用,分析对比了有中心无中心融合处理结构的优缺点,并提出了适合当前数据链网络现状的融合处理方式建议,对网络化多平台信息系统的信息融合架构设计、方案选择具有重要参考意义。     

Color impulsive noise removal based on quaternion representation and directional vector order-statistics

A new method for detecting and suppressing impulsive noise in color images is presented in this paper. The proposed method is a type of switching vector filters, where the impulse detection is based on the order-statistic information about the color samples in the horizontal, vertical, and diagonal directions. The new solution first uses quaternion-based representation of color differences and median deviation-based techniques to search for the edge direction with the maximum number of similar pixels, and then utilizes the samples aligning with this edge direction to judge whether the current pixel is noisy or not and control the switching between identity (no filtering) and vector median filtering actions. Extensive experimental comparisons exhibit the validity of the proposed approach by showing significant performance improvements over other well-known color image filtering techniques.     

光学相干层析图像的散斑去躁和边缘特征提取

提出采用各向异性扩散（AD）算法对光学相干层析（OCT）图像作噪声消除和边缘增强的预处理,然后结合改进的相位一致（PC）算法进行边缘特征提取,并引入巴特沃斯高通提升滤波进一步衰减低频噪声,增强高频边缘细节。对不同的OCT图像进行处理实验,结果表明,上述三种算法的综合应用,使OCT图像噪声得到有效抑制,轮廓清晰,特征部位得到加强。     

图像加密传送系统的设计与实现

在一些特殊的应用领域，一些场景图像需要通过网络或其他开放的通信手段发送到指定的工作点，供监控人员使用。由于其中可能存在着敏感信息和保密信息，需要对它们进行保护，防止泄漏。通过采用矩阵变换方法和局部数值调整方法，结合DSP技术实现局部图像加密系统，既保护传送图像信息的安全，又不影响合法用户对图像的使用，可有效地提高我国的远程监测监视能力。     

一种CCD相机的视频处理电路设计与噪声分析

为使CCD相机系统能够捕获到高信噪比的图像,介绍了一种视频处理器TDA9965的应用电路设计,简述了其内部组成框图及工作原理。利用某型号TDI CCD作为系统传感器,成功实现了对CCD输出模拟视频信号的量化处理,能够使相机系统完成实时采集图像等任务。同时分析了视频处理器电路设计对相机系统图像信噪比的影响,以电源噪声为干扰源,具体计算了在电路设计不合理和改进设计后两种情况下,CCD相机图像信噪比的变化,并通过试验测试验证,合理的电路设计可以使图像的信噪比提高20 dB以上,从而说明了视频处理电路合理设计的重要性,为高速高信噪比CCD相机的研制提供了技术基础。     

一种基于自适应结构的片上运动检测算法与实验

在CMOS图像传感器应用系统中,运动检测是降低系统功耗的一种重要手段.本文提出一种基于片上自适应结构的运动检测算法.该算法在不影响检测精度的情况下,通过抽样检测和两位比较,将需要运算的数据量降低到了传统算法的2.5 ‰;同时,算法实现了检测位和阈值的自适应结构以及抽样频率的可编程化,从而使运动检测能够适应更复杂的应用环境.实验结果表明,该算法能够满足实时性要求,检测精度可达99 %以上,对光线的适应能力强,并具有低功耗、抗噪声的特性.     

Design of a systolic-pipelined architecture for real-time enhancement of color video stream based on an illuminance-reflectance model

A high performance digital architecture for the implementation of a nonlinear image enhancement technique is proposed in this paper. The image enhancement is based on an illuminance-reflectance model which improves the visual quality of digital images and video captured under insufficient or non-uniform lighting conditions. The algorithm shows robust performance with appropriate dynamic range compression, good contrast, accurate and consistent color rendition. The algorithm contains a large number of complex computations and thus it requires specialized hardware implementation for real-time applications. Systolic, pipelined and parallel design techniques are utilized effectively in the proposed FPGA-based architectural design to achieve real-time performance. Approximation techniques are used in the hardware algorithmic design to achieve high throughput. The video enhancement system is implemented using Xilinx's multimedia development board that contains a VirtexII-X2000 FPGA and it is capable of processing approximately 63 Mega-pixels (Mpixels) per second.     

去除图像椒盐噪声的双向预测算法及其改进

在去除图像噪声的同时,如何避免图像细节信息的损失和边缘的模糊,是图像处理技术中的一个难点.针对灰度图像中存在的椒盐噪声问题,提出了基于双向预测算法的去噪方法.首先根据椒盐噪声的特点,判断图像像素是信号像素还是噪声像素.对于信号像素,保持灰度值不变;对于噪声像素,利用双向预测的方法来确定处理后该像素点的灰度值.针对上述方法中存在的不足之处,又提出了一种改进方案.改进方案在对噪声像素处理时,根据像素之间的相关性和像素本身的性质自适应地确定预测器的预测系数,提高了预测算法的去噪性能.实验结果表明,本文算法具有良好的去噪特性及细节保持特性.     

基于TI DSP的红外图像采集预处理系统的软硬件实现

介绍了一种基于高性能定点数字信号处理器(DSP)TMS320C6416的红外图像处理系统。本系统以DSP为核心处理器,辅以单片机统一系统时序,完成红外视频采集、图像增强和视频输出的功能,具有适应性、实用性强和调试方便的特点,在红外热成像系统中有着广泛的应用前景。     

基于CPLD和DSP的高速图像采集技术研究

介绍了一种基于复杂可编程逻辑器件(CPLD)和数字信号处理器(DSP)的图像采集系统.系统采用增强型视频输入处理芯片SAA7111A完成视频信号的A/D转换,大大减小了电路的复杂度;利用CPLD,采用全硬件方式实现了两组图像存储器的轮换存储;并利用CPLD极大的灵活性,巧妙地使两组存储器作为DSP与SAA7111A之间的共享内存,摆脱了传统双口RAM数据传输占用大量系统资源的瓶颈,实现了实时高速图像采集的设计目的.     

基于DSP6416的图像处理设计与实现

采用TMS320C6416作为系统的核心处理器,并应用适当的算法完成图像的编解码过程。该系统可以应用于通信科学,图像识别,新闻现场等诸多图像处理与传输领域。对系统的硬件资源选择、视频采集芯片SAA7111,系统的软件流程进行了详细的分析。系统不仅能够实现较高比例的数据压缩,而且还原图像的失真较小,具有较高的实用价值。     

基于小波变换和数学形态学的遥感图像边缘检测

由于遥感图像一般带有较大的噪声，通过实验表明，用传统的边缘检测方法效果不理想。采用小波方向性检测技术并结合数学形态学的方法，提出了一种基于小波变换和小尺度的数学形态学的遥感图像边缘检测方法。实验表明本算法计算有效，边缘定位准确，对噪声有一定的抑制作用，边缘检测效果明显。     

多级式红外预警图像处理系统设计与实现

针对红外预警系统分析可疑来袭目标时减少反应时间和降低虚警率之间的矛盾,提出了一种采用多级预警机制的红外预警实时图像处理系统设计方案,设置告警级别,针对不同探测与处理结果给出不同级别的告警信号。同时针对推扫式红外预警系统的成像特点,采用多路处理方法以提升系统实时性。硬件方面为满足多级预警与多路处理方法的需求,基于Xilinx公司的Virtex 5系列FPGA与TI公司TMS320C6455型高速DSP为核心处理器设计多核架构,开发了FPGA内部的DSP运算内核,增强了系统的运算能力。实验表明,采用多级红外预警和多路处理技术能够在满足虚警率要求的同时提升系统的实效性。