Application of the Bayesian Information Criterion to Keyframe Extracti

彬彬

1. Introduction

In most of the techniques to extract keyframes from motion capture

(mocap) data, criteria to guarantee the quality of keyframes

are provided by manually adjusting evaluation parameters. In this

study, the authors try to apply the Bayesian information criterion

(BIC) [Schwartz 1978] to keyframe extraction. BIC is a model-

selection criterion; models are evaluated under the tradeoff

between the goodness of fit to observed data and the model complexity.

Applying BIC allows us to automatically asses the quality

of keyframes under the tradeoff between the accuracy of interpolated

motions and the reduction of the number of keyframes.

2. Curve-Simplification Algorithm with BIC

Here, the curve-simplification algorithm [Lim et al. 2001] is

adopted as a keyframe-extraction method. In this algorithm, a

high-dimensional mocap-data curve is divided into two segments

at the point most distant from the straight line connecting the

endpoints of the curve. The point becomes the endpoint of each of

the new two straight lines representing a simplified curve, and is

regarded as a keyframe; this procedure is recursively repeated. In

this study, a curve is obtained in the joint-angle space in which the

exponential map is used instead of the axis-angle representation;

motion saliency is thereby more effectively reflected on a curve.

At each of the stages in the recursive process, the error between

the original curve u(n) and the simplified one ( ) SC u n ( n : frame

number) in the P-dimensional joint-angle space is calculated as

( ) ( ) ( ) SC ε n = u n − u n , and the time axis is treated as being divided

into K segments at keyframes. Under the assumption that ε has a

normal distribution at every segment, the log-likelihood function

L representing the goodness of fit is given as follows:

tc

秋天的落叶已飘远，冬日的暖阳已降临，春天的故事在萌芽，夏日的清凉在期待。新年的钟声提前为你敲响，HAPPYNEWYEAR！

菜刀吻电线

2012年祝你好事多赢，发点小财；好事不断，交点小运；马上升职，做个小官；得个表彰，露个小脸；生活无忧，喝点小酒；预祝新年快乐，眯眯小眼。龙年春节祝福语

C.R.CAN

先垫一块，再说鸟

C.R.CAN

加精、加亮滴铁子，尤其要多丁页丁页

奇

非常感谢，管理员设置了需要对新回复进行审核，您的帖子通过审核后将被显示出来，现在将转入主题

晃晃

不错不错，收藏了

铁锹 3D打印店铺

3D数模的CMM曲面检测技术简介




美国IND与日本3D Desigh联手打造宝马3系






3D打印复制Portal Gun传送门枪







全息3D立体影像的发展史







用相机和投影机实现1mm精度的3D扫描







Intel 3D晶体管来势汹汹_ARM毫不畏惧







评论称好莱坞3D难救中国电影产业





SYSTM by Incase：3D风IPhone 4保护壳

晃晃

你们都躲开，我来顶

C.R.CAN

无聊时可以刷屏幕 灌水 也可以试试 帖子的标题究竟可以写多长