多尺度人脸特征提取*

介绍了一种新的人脸特征提取的方法,首先在原始图像中找出人脸所在大致区域,然后对已经找出的人脸所在区域进行小波分解,并利用方块效应找出人眼及嘴部所在大致位置,最后提取眼、嘴的特征。试验结果表明,该方法对于人脸特征的提取具有较好的效果。     

梯度估计在眼睛特征提取中的应用

眼睛特征的提取在表情分析、人脸合成和人脸识别等应用中起着非常重要的作用.目前广泛使用的眼睛特征提取算法是基于模板匹配的算法和基于特征点的算法.然而基于模板匹配的算法通常需要进行多个参数的选择,而且匹配过程非常耗时;特征点的算法则存在准确度较低的问题.针对以上问题提出了一种基于梯度信息提取虹膜中心、虹膜外轮廓和眼睛角点等眼睛特征的算法,算法用改进霍夫变换提取虹膜中心和外轮廓.在获得虹膜中心点后,参照中心位置选择眼睛角点候选区域并对其梯度进行分析.依据角点附近梯度分布与其它区域梯度分布不同的性质定位角点.仿真结果表明提出的算法能有效的提取眼睛特征,在测试数据上得到了比其它算法更高的准确率和更快的速度.     

Change detection in desktop virtual environments: An eye-tracking study

It is common knowledge that attention is important for learning. We need to utilize attention in order to learn something efficiently and effectively. Similarly, we may also need to acquire familiarity with (i.e., learn) our surroundings in order to utilize our attention. In this study, learning is defined as a product of one’s exposure to natural visual stimuli. Using a virtual model of a natural scene, we investigate both attention and its relationship to learning, according to this definition. Specifically, our focus is the effect of environment familiarity on gaze direction. Our findings reveal that the factor of familiarity with one’s surroundings in virtual reality environments exerts a significant influence on peoples’ ability to detect a variety of specific changes that occur within scenes under their observation.     

A method of detecting and tracking irises and eyelids in video

We locate the eye corners, eyelids, and irises in every frame of an image sequence, and analyze the movements of the irises and eyelids to determine changes in gaze direction and blinking, respectively. Using simple models for the motions of the head and eyes, we determine the head-independent motions of the irises and eyelids by stabilizing for the head motion. The head-independent motions of the irises can be used to determine behaviors like saccades and smooth pursuit. Tracking the upper eyelid and using the distance between its apex and the center of the iris, we detect instances of eye closure during blinking. In experiments on two short image sequences, in one of which the subject was wearing glasses, we successfully located the irises in every frame in which the eyes were fully or partially open, and successfully located the eyelids 80% of the time. When motion information in the form of normal flow was used, the irises were successfully tracked in every frame in which the eyes were fully or partially open, and the eyelids were successfully located and tracked 90% of the time.     

CAT’S EYE — AN INTELLIGENT INVESTIGATION TOOL FOR URBAN PLANNING AND DESIGN

Under the backdrop of refinement of urban governance and the increasingly broad application of information technology, an urgent demand for intelligent investigation has emerged among urban planning and design professions. Cat’s Eye, an intelligent investigation tool developed by UrbanXYZ, operates with position information of survey photos and computational vision technology, realizing spatial mapping and photo management in investigations of medium- and small-scale planning and design projects. The Cat’s Eye applet is designed to collect information of spatial setting, facility / amenity conditions, and human behaviors and activities; and its PC terminal is developed for higher investigation needs such as result visualization, video analysis, and data management. This article introduces the product architecture, technical innovation, interface and operation, and investigation methods of Cat's Eye. Furthermore, by combining authentic cases, the article illustrates how Cat’s Eye investigates the spatial setting, facility / amenity, and human behaviors in survey areas. Finally, the article prospects the future of intelligent investigation tools.     

0.1%玻璃酸钠滴眼液原料分子量和灭菌条件的筛选

目的筛选0.1%玻璃酸钠滴眼液原料的分子量和滴眼液灭菌条件。方法选用高、中、低分子量的玻璃酸钠原料,配制0.1%玻璃酸钠滴眼液,分别在116℃×40 min,116℃×30 min,121℃×15 min的条件下热压灭菌,测定终产品的运动黏度、分子量和分子量分布。结果在3个灭菌条件下,低分子量组的样品灭菌后运动黏度低于或接近标准下限,高分子量组的样品灭菌后运动黏度高于或接近标准上限,中分子量组的样品灭菌后运动黏度均在标准范围内;相同分子量的样品,运动黏度和分子量下降幅度116℃×40 min条件下最大,121℃×15 min次之,116℃×30 min与121℃×15 min相当。结论中分子量的玻璃酸钠原料,121℃×15 min灭菌条件适合0.1%玻璃酸钠滴眼液的生产。     

丝网印刷在胶靴商标中的应用

丝网印刷的基本原理是丝网印版的网孔能够透过胶浆,使胶浆漏印在胶标凸起表面与丝网接触的部分。     

基于人脸识别的疲劳检测系统的软件实现

本文对人脸定位、识别,人眼定位,眼睛状态识别以及相关的图像处理技术进行了较为深入的研究,分析有关国际先进成果的不足之处,在借鉴和选取已有相关算法的基础上,设计并实现了一套适合于驾车疲劳预警的软件监测系统,并通过实验证实了系统的有效性,该系统可以推广应用于民用车载驾驶系统。     

视线跟踪过程中变形瞳孔的定位

在视线跟踪过程中,变形瞳孔的定位至关重要。针对眼部图像出现干扰情况下的变形瞳孔定位,该文提出了一种基于3点的随机采样一致性定位算法RANSAC_3,即利用随机采样到的2点(以及它们的梯度方向)和搜索获得的1个点来确定椭圆参数。由于该算法在确定参数时只需随机采样两个点,从而大大降低了采样到干扰点的几率,利用搜索到的第3点来决定是否对当前点进行参数计算,有效地解决了标准随机采样一致性定位算法中的无效采样和误差累积问题,提高了椭圆拟合效率和瞳孔定位精度。实验证明,该算法对变形瞳孔具有很好的定位效果,对光斑、睫毛、头发、眼镜框以及眼球运动模糊的引起的干扰具有较强的鲁棒性,并且定位速度快,可以达到实时要求。     

Progressive keratoconus in patients older than 48 years

PurposeTo report cases of progressive keratoconus (KC) in patients aged ≥48 years and the successful arrest of progression using corneal cross-linking (CXL) with riboflavin and ultraviolet-A light.ObservationsFive eyes from four patients with progressive KC aged 48, 48, 51 and 54 years are reported in this case series. All eyes were followed regularly after initial diagnosis. K_max was used as an indicator of progression and KC progressed at a rate of 1.4 diopters in 6 months and 14.6 diopters in 14 months. All patients eventually received CXL, and all were aged ≥50 years at the time of the procedure. One eye required two CXL procedures to successfully stabilize the patient’s cornea.ConclusionDespite the probability of KC progression strongly declining after the age of 40 years, it never becomes zero. It is therefore advisable to continue regular follow-up corneal tomography examinations in patients with KC, even in their fifth and sixth decades of life.