基于梯度矢量方向性分析的线裁剪算法

在传统线裁剪(seam carving)算法中梯度矢量的方向性是一个被忽略的因素,该文提出了一种新的基于梯度矢量方向性分析的线裁剪算法。首先利用随机纹理区域内梯度矢量方向散乱的特点,对局部区域的图像梯度矢量进行低通滤波,使算法能够提取更加合理的像素线路;接着又根据像素线路的走向不同,定义两个不同的像素能量函数,给予像素梯度矢量的x, y分量以不同的权值。实验结果图像显示,文中算法不仅可以更好地保护图像边缘等细节,还可以在整体上达到与原图像更加近似的视觉效果。定量分析结果也显示,相比其它算法该文算法在完整性距离和一致性距离两方面都取得了更好结果。     

基于图像像素划分的主动隐写分析

隐写分析的研究主要集中于隐写检测,而对主动隐写分析研究的较少。该文从隐写检测角度出发,将图像像素划分为不同类点,通过对信息嵌入、最低位平面置反带来的各类点频次变化的分析,提出一种针对空域图像LSB (Least Significant Bit) 替换隐写术的主动隐写分析方法,解决了主动隐写分析中的密钥恢复问题。所提出的方法物理意义直观,实现简单。实验结果表明,该方法在一定嵌入率范围内均可成功恢复隐写密钥。     

基于背景和像素的彩色车牌定位

提出结合车牌的背景差和像素分类实现彩色车牌定位算法。首先采用背景差法,即原图与背景图像相减,去除大量疑似车牌颜色特征的背景区域,缩小定位范围;然后统计车牌颜色RGB值,利用像素分类对车牌进行水平和垂直精确定位,确定车牌区域。实验表明,该方法定位准确率高,适用于任意背景、位置和光照下的车牌定位,明显克服了用车牌单一特征分析时难以解决的车牌区域变大的问题。     

重心坐标下曲线的像素级生成算法

对重心坐标下的曲线方程以及重心坐标下曲线的生成进行了研究,提出一和像素级的生成算法,由于只涉及到加减法,效率极高。     

基于像素运动的图像模糊机理与恢复技术

从像素运动的角度分析了因运动造成图像模糊的实际过程，根据模糊图像像素间的关系建立了一维和二维匀速直线运动所造成的模糊图像的模糊模型，进而由模糊过程的逆过程给出了恢复模型。最后对匀速直线运动造成的图像模糊进行了模拟和恢复，取得了令人满意的效果。     

Detection of single electrons by means of a Micromegas-covered MediPix2 pixel CMOS readout circuit

A small drift chamber was read out by means of a MediPix2 readout chip as a direct anode. A Micromegas foil was placed above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. We recorded many frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as δ-rays.     

激光打标设备的CAD/CAM系统开发

本文介绍了以TIF象素文件数据格式作为中间介质，实现激光打标设备的计算机辅助图形设计以及控制指令生成的CAD／CAM一体化系统开发的方法。     

Face and palmprint pixel level fusion and Kernel DCV-RBF classifier for small sample biometric recognition

Recently, multi-modal biometric fusion techniques have attracted increasing atove the recognition performance in some difficult biometric problems. The small sample biometric recognition problem is such a research difficulty in real-world applications. So far, most research work on fusion techniques has been done at the highest fusion level, i.e. the decision level. In this paper, we propose a novel fusion approach at the lowest level, i.e. the image pixel level. We first combine two kinds of biometrics: the face feature, which is a representative of contactless biometric, and the palmprint feature, which is a typical contacting biometric. We perform the Gabor transform on face and palmprint images and combine them at the pixel level. The correlation analysis shows that there is very small correlation between their normalized Gabor-transformed images. This paper also presents a novel classifier, KDCV-RBF, to classify the fused biometric images. It extracts the image discriminative features using a Kernel discriminative common vectors (KDCV) approach and classifies the features by using the radial base function (RBF) network. As the test data, we take two largest public face databases (AR and FERET) and a large palmprint database. The experimental results demonstrate that the proposed biometric fusion recognition approach is a rather effective solution for the small sample recognition problem.     

基于递归的二值图像连通域像素标记算法

在研究以前二值图像连通算法的基础上，提出了一种基于递归方法的二值图像连通域像素标记算法。通过对二值图像的扫描和分析可得到二值图像中的连通域划分和连通域的数目。算法主要包括两个步骤：对输入的二值图像进行一次扫描，得到所有目标像素的连通域划分和标记的等价对表；利用递归对等价对表进行分析，得到正确的连通标记划分和连通区域数目。实验结果表明，该算法对于任意复杂形状、任意数目(小于1 000)的连通区域都能正确检测。     

单电流传输器实现的Q增强二阶带通滤波器

本文提出了几种用单块电流传输器(CCII)实现的Q增强二阶带通滤波电路。这些电路使用的元件较已见报道的同类电路和用运算放大器(OA)实现的同类电路少;适当选择元件参数,还可实现RCD串联谐振器。