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921.
Bas‐relief is designed to provide 3D perception for the viewers under illumination. For the problem of bas‐relief generation from 3D object, most existing methods ignore the influence of illumination on bas‐relief appearance. In this paper, we propose a novel method that adaptively generate bas‐reliefs with respect to illumination conditions. Given a 3D object and its target appearance, our method finds an adaptive surface that preserves the appearance of the input. We validate our approach through a variety of applications. Experimental results indicate that the proposed approach is effective in producing bas‐reliefs with desired appearance under illumination. 相似文献
922.
空间机器人系统的自适应控制 总被引:56,自引:3,他引:56
对于载体姿态可控的空间机器人系统,本文给出了一种笛卡空间自适应控制算法,当系统的动力学参数未知时,该算法可以保证对手端期望位置轨迹的渐近跟踪,并且不需要测量关节加速度。应用文中算法对二杆平面空间机器人系统进行仿真研究。证实了算法的有效性。 相似文献
923.
X. Yuan D. Goldman A. Moghaddamzadeh N. Bourbakis 《Pattern Analysis & Applications》2001,4(4):272-282
In this paper, a fuzzy-like technique is presented that resolves several difficult issues related to image segmentation,
such as highlights and shadows. Large, relatively continuous, areas within an image are usually easy to segment, and the pixels
included within different segments are often determined by using derived edge information. However, in many cases, pixels
which lie between segments or in high frequency areas of an image cannot be easily categorised as belonging to any particular
segments. Typically, according to the dichromatic reflection model, these pixels may belong to the matte, highlight or shadow
area of the closest segment; or, in association with neighbouring pixels, they make up a separate smaller segment. The dichromatic
reflection model is applied here to merge highlight and shadow areas with matte areas in an image. By segmenting those pixels
into proper regions, the proposed fuzzy-like reasoning approach provides a more human-like segmentation of images. 相似文献
924.
This paper presents a variational algorithm for feature‐preserved mesh denoising. At the heart of the algorithm is a novel variational model composed of three components: fidelity, regularization and fairness, which are specifically designed to have their intuitive roles. In particular, the fidelity is formulated as an L1 data term, which makes the regularization process be less dependent on the exact value of outliers and noise. The regularization is formulated as the total absolute edge‐lengthed supplementary angle of the dihedral angle, making the model capable of reconstructing meshes with sharp features. In addition, an augmented Lagrange method is provided to efficiently solve the proposed variational model. Compared to the prior art, the new algorithm has crucial advantages in handling large scale noise, noise along random directions, and different kinds of noise, including random impulsive noise, even in the presence of sharp features. Both visual and quantitative evaluation demonstrates the superiority of the new algorithm. 相似文献
925.
Fantasy play and storytelling serve an important role in young children’s development. While computers are increasingly present
in the world of young children, there is a lack of computational tools to support children’s voices in everyday storytelling,
particularly in the context of fantasy play. We believe that there is a need for computational systems that engage in story-listening
rather than story-telling. This paper introduces StoryMat, a system that supports and listens to children’s voices in their
own storytelling play. StoryMat offers a child-driven, story-listening space by recording and recalling children’s narrating
voices, and the movements they make with their stuffed animals on a colourful story-evoking quilt. Empirical research with
children shows that StoryMat fosters developmentally advanced forms of storytelling of the kind that has been shown to provide
a bridge to written literacy, and provides a space where children engage in fantasy storytelling collaboratively with or without
a playmate. The paper addresses the importance of supporting young children’s fantasy play and suggests a new way for technology
to play an integral part in that activity. 相似文献
926.
Shahram Izadi Mike Fraser Steve Benford Martin Flintham Chris Greenhalgh Tom Rodden Holger Schnädelbach 《Personal and Ubiquitous Computing》2002,6(4):290-298
The Citywide project is exploring ways in which technology can provide people with rich and engaging digital experiences
as they move through physical space, including historical experiences, performances and games. This paper describes some initial
results and experiences with this project based upon two prototype demonstrators. In the first, we describe an application
in which a search party explores an archaeological site, uncovering enacted scenes within the virtual world that are of a
historical relevance to their particular physical location. In the second, we describe a museum experience where participants
explore an outdoors location, hunting for buried virtual artifacts that they then bring back to a museum for a more detailed
study. Our demonstrators employ a varied set of devices, including mobile wireless interfaces for locating hotspots of virtual
activity when outdoors, to give different experiences of the virtual world depending upon location, task, available equipment
and accuracy of tracking. We conclude by discussing some of the potential advantages of using an underlying shared virtual
world to support interactive experiences across extended physical settings. 相似文献
927.
Segmenting Traffic Scenes from Grey Level and Motion Information 总被引:8,自引:0,他引:8
This paper is concerned with an efficient estimation and segmentation of 2D motion from image sequences, with the focus on
traffic monitoring applications. In order to reduce the computational load to achieve real-time implementation, the proposed
approach makes use of simplifying assumptions that the camera is stationary, and that the projection of vehicles motion on
the image plane can be approximated by translation. We show that satisfactory results can be achieved even under such apparently
restrictive assumptions. The use of 2D motion analysis and the pre-segmentation stage significantly reduces the computational
load, and the region-based motion estimator gives robustness to noise and changes in the illumination conditions. 相似文献
928.
929.
Duminda Wijesekera Jaideep Srivastava Anil Nerode Mark Foresti 《Multimedia Systems》1999,7(6):486-499
Perception of multimedia quality, specified by quality-of-service (QoS) metrics, can be used by system designers to optimize
customer satisfaction within resource bounds enforced by general-purpose computing platforms. Media losses, rate variations
and transient synchronization losses have been suspected to affect human perception of multimedia quality. This paper presents
metrics to measure such defects, and results of a series of user experiments that justify such speculations. Results of the
study provide bounds on losses, rate variations and transient synchronization losses as a function of user satisfaction, in
the form of Likert values. It is shown how these results can be used by algorithm designers of underlying multimedia systems. 相似文献
930.
Mario Pukall Christian Kästner Walter Cazzola Sebastian Götz Alexander Grebhahn Reimar Schröter Gunter Saake 《Software》2013,43(2):153-185
Software is changed frequently during its life cycle. New requirements come, and bugs must be fixed. To update an application, it usually must be stopped, patched, and restarted. This causes time periods of unavailability, which is always a problem for highly available applications. Even for the development of complex applications, restarts to test new program parts can be time consuming and annoying. Thus, we aim at dynamic software updates to update programs at runtime. There is a large body of research on dynamic software updates, but so far, existing approaches have shortcomings either in terms of flexibility or performance. In addition, some of them depend on specific runtime environments and dictate the program's architecture. We present JavAdaptor , the first runtime update approach based on Java that (a) offers flexible dynamic software updates, (b) is platform independent, (c) introduces only minimal performance overhead, and (d) does not dictate the program architecture. JavAdaptor combines schema changing class replacements by class renaming and caller updates with Java HotSwap using containers and proxies. It runs on top of all major standard Java virtual machines. We evaluate our approach's applicability and performance in non‐trivial case studies and compare it with existing dynamic software update approaches. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献