基于分层弹性运动分析的非刚体跟踪方法

Non-rigid Tracking Method Based on Layered Elastic Motion Analysis

采用时–空分层的弹性运动跟踪策略,提出了一种分析长时运动稳定结构与短时运动局部变化的非刚体运动跟踪方法.首先,基于序贯形状聚类的分段弹性运动跟踪模型,将整段图像序列分割成若干子段,并利用弹性运动分析方法得到子段内各帧边缘点的对应关系和各类的平均形状,获取短时局部运动变化细节.然后,通过基于贝叶斯网的整体搜索算法寻找时序上相邻聚类平均形状之间的对应关系,进而得到整段运动的公共形状,用于表示长时运动稳定结构.通过计算公共形状与各类平均形状之间的变形关系,可以建立各聚类平均形状之间的对应关系,实现分段运动的连接.本方法的特点是不依赖先验模型、通用性好、目标的描述能力强.实验表明,本方法与现有不依赖模型的方法相比,具有更好的长时稳定性和更高的跟踪精确度.

In this paper, we present a spatial-temporal layered elastic motion tracking method to estimate long-term stable structures and short-term local motions for non-rigid targets. First, the sequence is segmented into several pieces by sequential shape clustering based a piece-wise elastic motion tracking model, the correspondence among frames in the same segment and the mean shape of all clusters are calculated by piece-wise elastic motion tracking. Then, we use a Bayesian network based global search method to find the correspondence of mean shapes of adjoining clusters and extract the common shape of the entire sequence. The proposed method, which does not require prior shape models, is adaptive to and descriptive for general objects. The experiments on non-rigid targets validate both the long-term stability and the detailed accuracy of our proposed method.