基于多尺度top-hat变换的自适应彩色图像增强

针对传统彩色图像增强过程中的过度增强及空间变化所引起的信息丢失现象,在RGB空间提出一种基于数学形态学top-hat算法,以各分量标准差权重比例为调控因子的彩色图像增强方法。首先,提取R、G、B通道多尺度下的亮、暗细节特征,然后利用控制因子对有应用价值的细节特征进行增强,最后组合三个分量,得到增强的目标图像。实验结果表明,该方法能有效增强图像对比度,避免过度增强,且能很好地保持亮度,视觉效果良好。     

A New Medical Image Enhancement Based on Human Visual Characteristics

Study of image enhancement shows that the quality of image heavily relies on human visual system. In this paper, we apply this fact effectively to design a new image enhancement method for medical images that improves the detail regions. First, the eye region of interest （ROI） is segmented; then the Un-sharp Masking （USM） is used to enhance the detail regions. Experiments show that the proposed method can effectively improve the accuracy of medical image enhancement and has a significant effect.     

Investigation of Raman enhancement in hydrothermally roughened SERS-active substrates

In this work, we study surface enhanced Raman spectroscopy (SERS) active substrates for the detection of Rhodamine 6G. To examine the electromagnetic enhancement, we apply the finite-difference time-domain (FDTD) algorithm to analyze the structures by solving a set of coupled Maxwell's equations (Ampere's Law and Faraday's Law) in differential form. The field enhancements are thus investigated in the visible regime with the wavelength of 633 nm. In our experimental measurement, the surface enhanced Raman scattering signals from the surface of substrates with 12-hour treatment and without treatment are performed and compared. Through the three-dimensional (3D) FDTD calculation, we find that the hydrothermally 12-hour treated samples possess significantly vertical variations of surface and thus have relatively larger field enhancement than those without treated. Consequently, it implies a strong positive effect on the surface enhancement which is consistent with the measured intensity.     

A novel algorithm of fingerprint encryption using minutiae-based transformation

This paper presents a novel algorithm of fingerprint encryption which transforms fingerprint minutiae and performs matching in the transformed form. If an encrypted template is compromised, it can be cancelled by choosing just another transformed template. In our algorithm, a circular region is constructed around each minutia and non-invertible transformation is applied to all regions but only transformed regions are stored in the database. The proposed algorithm improves the accuracy of verification compared to related fuzzy vault systems. Experimental results show the comparative performance of matching using both transformed and original data. We find that transformed matching also has an impressive accuracy and speed.     

基于Gabor滤波器的指纹图像增强算法

介绍了一种基于Gabor滤波器的指纹图像增强算法,该方法对传统的Gabor滤波器的参数和大小进行了优化。实验表明这种算法具有很好的处理效果。     

一种分布式网络指纹识别系统

文章介绍了一种分布式网络指纹识别系统NBFIS(Network-BasedFingerprintIdentifyingSystem)。首先提出模型框架,并对其关键技术特别是指纹图像处理技术及面向对象的数据库技术进行讨论。实现了NBFIS系统的原型并给出实验和性能测试结果。     

自动报靶系统研究综述

介绍了一种基于机器视觉的自动报靶系统,该系统利用CCD摄像机不间断地对靶面进行观测,根据采集的靶面图像的特点和变化,利用计算机图像识别技术检测靶面图像中的真实弹点,然后通过弹点在靶面图中的位置来对弹点区域进行编码。在观测过程中,采用图像灰度配准与增强技术、图像的几何配准技术和小波变换等算法来解决由于光照变化、大风等干扰因素对识别精度的影响。在实际应用中,能够达到较高精度,并能大大减少错报和漏报的情况,该系统精度高、成木低、完全可靠,能够很好地应用于部队训练和射击比赛中有着重要的实际意义和良好的应用前景。     

Simultaneous speckle reduction and contrast enhancement for ultrasound images: Wavelet versus Laplacian pyramid

Speckle can be described as random multiplicative noise. It hampers the perception and extraction of fine details in the image. Speckle reduction techniques are applied to ultrasound images in order to reduce the noise level and improve the visual quality for better diagnoses. It is also used as preliminary treatment before segmentation and classification. Several methods have been proposed for speckle reduction in ultrasound images. Multiscale contrast enhancement has proven to be very efficient for x-ray images. A recent study by Dippel et al. doing a comparison, contrast enhancement of radiographs (x-ray and mammography), between the Laplacian pyramid and the wavelet one proves that the Laplacian pyramid method gives a better result than the wavelet one; the filtering aspect was not taken into account. In ultrasound images a strong contrast variation exists which is different from x-ray and mammography. In this paper a wavelet pyramid with simultaneous speckle reduction and contrast enhancement was applied for the first time on ultrasound images with the area of interest and compared to a Laplacian enhancement pyramid. The optimum choice of wavelet bases for ultrasound images is investigated in this study. In order to realize a fair comparison, the same nonlinear modification in both multiscale schemes is used. The comparison proves that the wavelet pyramid gives a much better result than the Laplacian one for simultaneous speckle reduction and contrast enhancement of ultrasound images. The text was submitted by the author in English. Ali Samir Saad, 1964. 1996 PhD in image processing, Polytechnics School of the Engineering University of Nantes, France. 1993 Masters in Electronics. 1990 Masters in Digital Image Processing, Institute of Computer Sciences and Communication University of Rennes, France. 1989 BS in Electrical Engineering, University of Saint-Etienne. Academy of Lyon, France. 1996–2000 Research associate at the National Center for Macromolecular Imaging. Baylor, Houston, Texas. Assistant professor at King Saud University, Dept. of Biomedical Technology. Area of research in medical image processing and analysis, 23 publications, member of the American Association for the Advancement of Sciences. Marquis Who’s Who in the World; Cambridge Blue Book 2006.     

一种基于指纹识别的网络通信安全平台

在网络通信中,由于密码体制的一些不安全性,使得信息在网络上传输的安全性受到威胁,提出了一种基于指纹识别的通信安全平台,在一定程度上可以提高通信的安全性。     

Algorithmic and architectural design for real-time and power-efficient Retinex image/video processing

This paper presents novel algorithmic and architectural solutions for real-time and power-efficient enhancement of images and video sequences. A programmable class of Retinex-like filters, based on the separation of the illumination and reflectance components, is proposed. The dynamic range of the input image is controlled by applying a suitable non-linear function to the illumination, while the details are enhanced by processing the reflectance. An innovative spatially recursive rational filter is used to estimate the illumination. Moreover, to improve the visual quality results of two-branch Retinex operators when applied to videos, a novel three-branch technique is proposed which exploits both spatial and temporal filtering. Real-time implementation is obtained by designing an Application Specific Instruction-set Processor (ASIP). Optimizations are addressed at algorithmic and architectural levels. The former involves arithmetic accuracy definition and linearization of non-linear operators; the latter includes customized instruction set, dedicated memory structure, adapted pipeline, bypasses, custom address generator, and special looping structures. The ASIP is synthesized in standard-cells CMOS technology and its performances are compared to known Digital signal processor (DSP) implementations of real-time Retinex filters. As a result of the comparison, the proposed algorithmic/architectural design outperforms state-of-art Retinex-like operators achieving the best trade-off between power consumption, flexibility, and visual quality.