基于内容的图像检索与MPEG-7

本文对基于内容的图像检索的研究现状以及关键技术进行了分析,介绍了MPEG-7标准的相关内容,并在此基础上提出一种基于MPEG-7标准的图像检索系统模型.     

MPEG-7的视频标准及其在IPTV中的应用

该文介绍了基于内容的多媒体检索MPEG-7中的视频标准及其描述工具,包括视频的主要元素和基本结构以及其各种视频相关描述符。并在MPEG-7基础上提出在IPTV中的基于内容的图像检索系统的基本思想,以及应用于视频分割和图形搜索的算法．通过分析图像的视觉特征和上下文联系来进行检索。     

MPEG视觉标准的又一次飞跃：MPEG-7

MPEG-7是用来描述多媒体内容的视觉标准，目前还处于应用发展阶段。它明确定义了具体的描述符，这些描述符允许用户或客户利用该压缩标准测量图像或视频的相似性，同时，还可以有效地识别、过滤或浏览图像或视频。更特别的是，MPEG-7描述的内容包括颜色、纹理、形状、全局运动或目标物体运动等。本文则概述了MPEG-7标淮的目的、方法和主要的内容。     

综合MPEG 7中纹理和颜色特征的图像检索方法*

在基于内容的图像检索中, 颜色和纹理是图像检索使用最频繁、最重要的两个视觉特征.但是仅基于一种特征的方法只能表达图像的部分属性.为此提出了综合利用MPEG-7中建议的纹理特征的边缘直方图描述符和颜色特征的主颜色和颜色布局描述符进行检索的方法,并依据MPEG-7中的评价准则评价检索结果.实验结果表明,综合特征检索更符合人的视觉感受要求,检索效果更好.     

基于MPEG-7主色描述符的图像检索

主色描述符作为MPEG-7的一种颜色描述子被广泛的应用于图像检索。通过一种有效的,结构紧凑的,直观的模式,主色描述符描述了一幅图像中的具有代表性的颜色特征。一种新的基于固定数目的MPEG-7主色描述符的图像检索算法被提出。特征提取的过程不再需要阙值的干预以及主色数目固定为8个。直方图相交算法用来衡量特征,从而简化了相似度的计算。实验结果表明,此方法的查准率和查全率高于非固定数目的主色检索方法。     

MPEG-7标准在电影动画素材检索中的应用

在电影动画的制作过程中，会产生各种类别的素材资料，如果能充分地利用这些现有的资料进行新的电影制作，将会大大缩短制作周期、提高工作效率、减少投资。在制作电影的过程中，能快速检索找到所需要的素材是非常必要的。时MPEG-7标准中的颜色特征如何在电影素材库中进行检索进行了研究，并给出一套实验系统。     

DCD用于相关反馈的自然图像检索

基于内容的图像检索是多媒体应用研究领域的一项关键技术.传统的CBIR系统一般采用基于图像的低级物理特征进行特征匹配,MPEG-7标准的提出为图像内容特征的提取与描述提供了一种新型简便的方法,本文讨论了应用MPEG-7的主体颜色描述符DCD对图像特征提取和表示的方法,并在图像检索中的应用研究基础之上,提出了在使用相关反馈的图像检索中的改进方案,实现了基于DCD特征描述的自然图像检索.对于1350幅的数字图象组成的数据集进行了实验,并对实验结果进行分析,大部分结果是令人满意的,提高了基于内容的图像检索的精度.     

MPEG-7标准及其在多媒体信息中的应用

MPEG-7标准(多媒体内容描述接口)为各类多媒体信息提供一种标准化的描述,为日渐庞大的多媒体信息管理和迅速检索提供了许多方法和参考工具。介绍了MPEG-7的标准,阐述了MPEG-7的范围,应用等等。MPEG-7具有较强的灵活性、可扩展性,应用广泛,必将促进多媒体技术快速发展。     

MPEG视觉标准的又一次飞跃：MPEG-7（二）

在《安全自动化》第97期中，作者详细介绍了MPEG-7作为描述多媒体内容的视觉标准，目前所处的应用发展阶段，以及具体的制定．应用和发展情况。紧承上回，本文将简单介绍MPEG-7的视觉描述符。这些描述符允许用户或客户利用该视觉标准测量图像或视频的个似性，同时，还可以有效地识别，过滤或浏览图像或视频。[编者按]     

The effect of banner animation on fixation behavior and recall performance in search tasks

Previous findings suggested that banner ads have little or no impact on perceptual behavior and memory performance in search tasks, but only in browsing paradigms. This assumption is not supported by the present eye-tracking study. It investigates whether task-related selective attention is disrupted depending on the animation intensity of banner ads when users are in a search mode as well as the impact of banner animation on perceptual and memory performance.     

浅析目前动漫教学中存在的误区

动漫教学在当今高校教育中所占比例越来越重,然而,由于诸多方面原因,当前动漫教学过程存在一些误区。本文从动漫基础教学、动漫教学的本土原创性和动漫教学培养目标几方面入手,旨在找出造成动漫教学重借鉴轻原创、重西方轻中国、重技术轻艺术的根本原因,以提高教学水平。     

Using animation to help students learn computer algorithms

This paper compares the effects of graphical study aids and animation on the problem-solving performance of students learning computer algorithms. Prior research has found inconsistent effects of animation on learning, and we believe this is partly attributable to animations not being designed to convey key information to learners. We performed an instructional analysis of the to-be-learned algorithms and designed the teaching materials based on that analysis. Participants studied stronger or weaker text-based information about the algorithm, and then some participants additionally studied still frames or an animation. Across 2 studies, learners who studied materials based on the instructional analysis tended to outperform other participants on both near and far transfer tasks. Animation also aided performance, particularly for participants who initially read the weaker text. These results suggest that animation might be added to curricula as a way of improving learning without needing revisions of existing texts and materials. Actual or potential applications of this research include the development of animations for learning complex systems as well as guidelines for determining when animations can aid learning.     

Optimized keyframe extraction for 3D character animations

In this paper, we propose a new method to automatically extract keyframes from animation sequences. Our method can be applied equally to both skeletal and mesh animations. It uses animation saliency computed on the original data to help select the group of keyframes that can reconstruct the input animation with less perception error. For computational efficiency, we perform nonlinear dimension reduction using locally linear embedding and then carry out the optimal search in much lower‐dimensional space. With this approach, reconstruction of the animation from the extracted keyframes shows much better results as compared with earlier approaches. Copyright © 2012 John Wiley & Sons, Ltd.     

基于改进群搜索优化算法的群体路径规划方法

针对群体动画中传统路径规划算法搜索时间长、寻优能力差等问题,提出一种利用群搜索算法进行多线程路径规划的方法。该方法首先将模拟退火算法引入到搜索模式中,克服算法易陷入局部最优的问题;其次,通过结合多线程和路径随机拼接技术,将算法应用到路径规划中。仿真实验表明该算法无论在高维还是低维情况下都具有较好的全局收敛性,能够很好地满足在复杂动画环境下路径规划的要求。     

血细胞动画素材的创建

人体血细胞的数字化在许多领域都有所应用,在动画制作中“血细胞”成为常用的素材。文章介绍了采用通用的3DsMax创作平台。实现血细胞从模型、材质、动画到渲染输出整个素材创建的过程和方法,通过实例验证了这一方法能够有效提高项目制作的速度。     

Real-time control of human actions using inertial sensors

Our study proposes a new local model to accurately control an avatar using six inertial sensors in real-time.Creating such a system to assist interactive control of a full-body avatar is challenging because control signals from our performance interfaces are usually inadequate to completely determine the whole body movement of human actors.We use a pre-captured motion database to construct a group of local regression models,which are used along with the control signals to synthesize whole body human movement.By synthesizing a variety of human movements based on actors’control in real-time,this study verifies the effectiveness of the proposed system.Compared with the previous models,our proposed model can synthesize more accurate results.Our system is suitable for common use because it is much cheaper than commercial motion capture systems.     

基于文本和视觉特征融合的Web动画素材标注

为了提高对Web动画素材的组织、管理,该文提出了基于文本特征和视觉特征融合的Web动画素材标注算法。首先利用自动提取的Web动画素材上下文信息,结合Web动画素材名称、页面主题、URL以及ALT等属性组成特征集,提取出文本关键字;然后利用视觉与标注字之间的相关性,对自动提取的标注字进行过滤,实现Web动画素材的自动标注。实验表明该文提出的基于文本特征和视觉特征融合的Web动画素材标注算法可有效地应用于Web动画素材自动标注。     

The role of spatial ability in learning from instructional animations - Evidence for an ability-as-compensator hypothesis

In two experiments, the role of spatial ability in learning from an instructional animation versus a series of static pictures was studied. In both experiments, a statistical interaction of spatial ability and type of visualization was obtained: Low-spatial ability students showed poor learning outcome when learning from pictures while high-spatial students did not; when learning from animation, however, learning outcome was independent from spatial ability. The results are in line with an ability-as-compensator hypothesis which states that constructing mental animations from non-dynamic materials needs spatial ability; with animated learning materials, however, spatial ability is not required. No overall differences between static pictures and animation were found.     

试谈高职院校《Flash动画制作》教学

根据《Flash动画制作》课程的特点,从教材选择、教学方法、教学模式、教学观念、教学手段等多方面进行了教学改革探讨,以培养学生动画制作和创新思维的能力,实现了高职院校专门培养技能型人才的教学目标。