Novel approach for region merging and image segmentation for human-computer interaction

For the purpose of human-computer interaction (HCI), a vision-based gesture segmentation approach is proposed. The technique essentially includes skin color detection and gesture segmentation. The skin color detection employs a skin-color artificial neural network (ANN). To merge and segment the region of interest, we propose a novel mountain algorithm. The details of the approach and experiment results are provided. The experimental segmentation accuracy is 96.25%. (C) 2003 Society of Photo-Optical Instrumentation Engineers.

basic research in computer science and software engineering at sklcs

The State Key Laboratory of Computer Science (SKLCS) is committed to basic research in computer science and software engineering. The research topics of the laboratory include: concurrency theory, theory and algorithms for real-time systems, formal specifications based on context-free grammars, semantics of programming languages, model checking, automated reasoning, logic programming, software testing, software process improvement, middleware technology, parallel algorithms and parallel software, computer graphics and human-computer interaction. This paper describes these topics in some detail and summarizes some results obtained in recent years.

虚拟现实人机交互的eGOMS模型研究

采用心理学和计算机技术相交叉的研究方法,对人机交互中人的认知过程的人类视知觉特征和心理加工机制与特点等进行了细致的探讨;结合虚拟环境中人机交互过程的不确定性、连续性和实时反馈性以及交互可用性评价指标的多样性等特点,提出了适用于虚拟现实人机交互的扩展GOMS(eGOMS)模型,克服了传统GOMS模型要求精确的用户操作、交互界面与实际应用相分离及评价指标单一的不足.以eGOMS模型为基础对PIBG交互范式进行了评估,PIBG为VR用户界面提供自然、隐式交互的手段,从而大大降低了用户在虚拟环境下交互的认知负荷.

construction of feature-matching perception in virtual assembly

An important characteristic of virtual assembly is interaction. Traditional di-rect manipulation in virtual assembly relies on dynamic collision detection, which is very time-consuming and even impossible in desktop virtual assembly environment. Feature-matching isa critical process in harmonious virtual assembly, and is the premise of assembly constraint sens-ing. This paper puts forward an active object-based feature-matching perception mechanism and afeature-matching interactive computing process, both of which make the direct manipulation in vir-tual assembly break away from collision detection. They also help to enhance virtual environmentunderstandability of user intention and promote interaction performance. Experimental resultsshow that this perception mechanism can ensure that users achieve real-time direct manipulationin desktop virtual environment.

Image Ratio Features for Facial Expression Recognition Application

Video-based facial expression recognition is a challenging problem in computer vision and human-computer interaction. To target this problem, texture features have been extracted and widely used, because they can capture image intensity changes raised by skin deformation. However, existing texture features encounter problems with albedo and lighting variations. To solve both problems, we propose a new texture feature called image ratio features. Compared with previously proposed texture features, e. g., high gradient component features, image ratio features are more robust to albedo and lighting variations. In addition, to further improve facial expression recognition accuracy based on image ratio features, we combine image ratio features with facial animation parameters (FAPs), which describe the geometric motions of facial feature points. The performance evaluation is based on the Carnegie Mellon University Cohn-Kanade database, our own database, and the Japanese Female Facial Expression database. Experimental results show that the proposed image ratio feature is more robust to albedo and lighting variations, and the combination of image ratio features and FAPs outperforms each feature alone. In addition, we study asymmetric facial expressions based on our own facial expression database and demonstrate the superior performance of our combined expression recognition system.

Behavioral responses of tilapia (Oreochromis niloticus) to acute fluctuations in dissolved oxygen levels as monitored by computer vision

Behavioral and ventilatory parameters have the possibility of predicting the stress state of fish in vivo and in situ. This paper presents a new image-processing algorithm for quantifying the average swimming speed of a fish school in an aquarium. This method is based on the alteration in projected area caused by the movement of individual fish during frame sequences captured at given time intervals. The image enhancement method increases the contrast between fish and background, and is thus suitable for use in turbid aquaculture water. Behavioral parameters (swimming activity and distribution parameters) and changes in ventilation frequency (VF) of tilapia (Oreochromis niloticus) responded to acute fluctuations in dissolved oxygen (DO) which were monitored continuously in the course of normoxia, falling DO level, maintenance of hypoxia (three levels of 1.5, 0.8 and 0.3 mg l(-1)) and subsequent recovery to normoxia. These parameters responded sensitively to acute variations in DO level; they displayed significant changes (P < 0.05) during severe hypoxia (0.8 and 0.3 mg l(-1) level) compared with normoxic condition, but there was no significant difference under conditions of mild hypoxia (1.5 mg l(-1) level). There was no significant difference in VF between two levels of severe hypoxia 0.8 and 0.3 mg l(-1) level during the low DO condition. The activity and distribution parameters displayed distinguishable differences between the 0.8 and 0.3 mg l(-1) levels. The behavioral parameters are thus capable of distinguishing between different degrees of severe hypoxia, though there were relatively large fluctuations. (c) 2006 Elsevier B.V. All rights reserved.

基于刺激－反应相容性的汉语拼音和弦键盘的实验研究

Stimulus-Response Compatibility is a key concept in human-machine interaction. It is proved that to map stimulus to response according to salient-feature coding principle will get a compatible pair. In the designing of Chinese Pinyin Code inputting devices, stimulus-response compatibility will bring the device with features of ease of use and ease of learning. In this research, Response time and error rates of two designs of salient-feature coding principle and one design of random mapping were tested along with the QWERTY keyboard. Cross-modal Compatibility Effects were found, and no significant difference between two salient-feature coding types, both on response time and error rates; but response time has shown difference between salient-feature coding designs and random mapping design. Compared with the QWERTY keyboard group, the error rates of subjects of chord keyboard group showed no significant differences. But subjects assigned to the QWERTY keyboard group have a shorter response time. One possible reason is the subjects of chord keyboard group only at beginner skill after at most 6 hours practice whereas subjects of QWERTY group were at least at novice level after take a foundation of computer class at their own college.

Lentivirus介导表达多基因的人胚基因工程神经干细胞的实验研究

目的:探索以Lentivirus为载体,构建同时携带并表达多基因的基因工程人胚神经干细胞(hum an neu鄄ral stem cell,hNSC)的可行性,为脊髓损伤治疗的研究提供材料。方法:培养和鉴定hNSC;用携带绿色荧光蛋白(green fluorescence protein,GFP)和神经营养因子-3(neurotrophic factor-3,NT-3)的Lentivirus转染hNSC;用荧光显微镜观察、鼠胚背根神经结培养(dorsal root ganglion,DRG)和Slot blot等方法检测基因工程hNSC的多基因表达情况。结果:培养获得了大量的hNSC;荧光显微镜观察到几乎100%的hNSC表达GFP;基因工程hNSC的培养液能促使大鼠DRG旺盛生长;Slot blot检测到基因工程hNSC能高效分泌NT-3蛋白。结论:以Lentivirus为载体能构建同时携带并稳定表达多基因的基因工程hNSC,为脊髓损伤治疗的基础研究及进一步临床应用提供了有价值的细胞资源。

Design and path planning for a remote-brained service robot

This article introduced an effective design method of robot called remote-brain, which is made the brain and body separated. It leaves the brain in the mother environment, by which we mean the environment in which the brain's software is developed, and talks with its body by wireless links. It also presents a real robot TUT06-B based on this method which has human-machine interaction, vision systems, manipulator etc. Then it discussed the path planning method for the robot based on ant colony algorithm in details, especially the Ant-cycle model. And it also analyzed the parameter of the algorithm which can affect the convergence. Finally, it gives the program flow chat of this algorithm.

使用概率规则文法评估人机界面可用性

提出一种在界面系统设计规约的基础上使用的可用性评估方法.首先使用有限状态自动机抽象界面系统设计,根据概率规则文法对有限状态自动机的状态转换概率进行预测;然后结合用户的熟练程度提出了界面可用性评估算法;最后讨论了一个手机界面的可用性计算实例.文中方法能够在界面系统生命周期的早期使用,以较早地对不同设计方案进行比较,降低开发风险.

自然交互研究——笔式简谱编辑器的设计与实现

自然交互是指用户可以用自己熟悉的日常技能与计算机进行交互。中国有大量的音乐爱好者使用简谱,但是针对简谱编辑的编辑软件却相对较少,并且现有软件的交互方式不够自然,降低了用户对软件的使用效率。他们需要一种更自然、更方便使用的简谱编辑软件。该文介绍了一个基于笔式输入的简谱编辑器原型系统的设计和实现。基于对现有软件、简谱特性和可利用的新技术的综合分析,设计并实现了这个原型系统。对此原型系统进行了非正式的用户实验之后,对结果进行了分析,并提出了修改的方案。

Color to Gray: Visual Cue Preservation

Both commercial and scientific applications often need to transform color images into gray-scale images, e. g., to reduce the publication cost in printing color images or to help color blind people see visual cues of color images. However, conventional color to gray algorithms are not ready for practical applications because they encounter the following problems: 1) Visual cues are not well defined so it is unclear how to preserve important cues in the transformed gray-scale images; 2) some algorithms have extremely high time cost for computation; and 3) some require human-computer interactions to have a reasonable transformation. To solve or at least reduce these problems, we propose a new algorithm based on a probabilistic graphical model with the assumption that the image is defined over a Markov random field. Thus, color to gray procedure can be regarded as a labeling process to preserve the newly well-defined visual cues of a color image in the transformed gray-scale image. Visual cues are measurements that can be extracted from a color image by a perceiver. They indicate the state of some properties of the image that the perceiver is interested in perceiving. Different people may perceive different cues from the same color image and three cues are defined in this paper, namely, color spatial consistency, image structure information, and color channel perception priority. We cast color to gray as a visual cue preservation procedure based on a probabilistic graphical model and optimize the model based on an integral minimization problem. We apply the new algorithm to both natural color images and artificial pictures, and demonstrate that the proposed approach outperforms representative conventional algorithms in terms of effectiveness and efficiency. In addition, it requires no human-computer interactions.

A Relay Level Set Method for Automatic Image Segmentation

This paper presents a new image segmentation method that applies an edge-based level set method in a relay fashion. The proposed method segments an image in a series of nested subregions that are automatically created by shrinking the stabilized curves in their previous subregions. The final result is obtained by combining all boundaries detected in these subregions. The proposed method has the following three advantages: 1) It can be automatically executed without human-computer interactions; 2) it applies the edge-based level set method with relay fashion to detect all boundaries; and 3) it automatically obtains a full segmentation without specifying the number of relays in advance. The comparison experiments illustrate that the proposed method performs better than the representative level set methods, and it can obtain similar or better results compared with other popular segmentation algorithms.