Collaborative Research: Nonparametric Theory on Manifolds of Shapes and Images, with Applications to Biology, Medical Imaging and Machine Vision

合作研究：形状和图像流形的非参数理论及其在生物学、医学成像和机器视觉中的应用

• 批准号: 0806011
• 负责人: Rabindra Bhattacharya
• 金额: $ 16万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0806011&HistoricalAwards=false
• 关键词: Collaborative; Research; Nonparametric; Theory; Manifolds

Much of the focus of this collaborative project is on the analysis of landmark based shapes in which a k-ad, i.e., a set of k points or landmarks on an object or a scene are observed in 2-D or 3-D, usually with expert help, for purposes of identification, discrimination, or diagnostics. Depending on the way the data are collected or recorded, the appropriate shape of an object is the maximal invariant specified by the space of orbits under a group G of transformations. In particular, Kendall's shape spaces of k-ads are invariant under scaling and Euclidean rigid motions. While this is a proper choice for many problems in biology and medical imaging, other notions of shape such as affine shape and projective shape are important in machine vision and bioinformatics. All these spaces are differentiable manifolds, often with natural Riemannian structures for measuring lengths and angles. The statistical analysis based on Riemannian structures is said to be intrinsic. In other cases, proper distances are sought via an equivariant embedding of the manifold M in a vector space E. Corresponding statistical analysis is called extrinsic. Finding proper Riemannian structures and equivariant embeddings is one of the objectives of this project, which is crucial for the statistical inference proposed. Establishing broad conditions for the existence of the Fre´chet mean, as the unique minimizer of the Fre´chet function the expected squared distance from a Q-distributed random shape is important for statistical inference; and it is a goal of the project to pursue, especially for intrinsic analysis where it has remained an outstanding open problem from the inception of shape theory. Reconstruction of a scene from two (ormore) aerial photographs taken from a plane is one of the research problems in affine shape analysis. Potential applications of projective shape analysis proposed here include face recognition and robotics-for robots to visually recognize a scene.Statistical analysis of data on geometric objects, or manifolds, is an exciting and challenging field of research, where statistical theory and differential geometry are inextricably intertwined, and implementation requires innovative algorithms and high speed computation. The project proposed here deals with the development of nonparametric methodology in this context, which must also resolve associated geometric issues and problems of implementation. Past progress in this field by the PIs has laid the foundation for the present project. The statistical analysis proposed has wide ranging applications, especially in biology and bioinformatics, health sciences, and machine vision. Under this project, the PIs plan to train both undergraduate and graduate students, as well as at least one postdoctoral fellow, in theory and in its practical implementation. This continues much further the present activities of the PIs in this regard. In addition, computational algorithms and codes are made available on websites to create and disseminate this research and its applications.

这个合作项目的大部分重点是对基于地标的形状的分析，其中k-ad，即，通常在专家的帮助下，以2-D或3-D的方式观察对象或场景上的一组k个点或界标，以用于识别、辨别或诊断的目的。根据收集或记录数据的方式，物体的适当形状是由变换群G下的轨道空间指定的最大不变量。特别地，Kendall的形状空间的k-广告下的缩放和欧几里得刚性运动是不变的。虽然这是生物学和医学成像中许多问题的正确选择，但形状的其他概念（如仿射形状和投影形状）在机器视觉和生物信息学中很重要。所有这些空间都是可微流形，通常具有用于测量长度和角度的自然黎曼结构。基于黎曼结构的统计分析被认为是内在的。在其他情况下，通过流形M在向量空间E中的等变嵌入来寻求适当的距离。相应的统计分析被称为外在的。寻找合适的黎曼结构和等变嵌入是这个项目的目标之一，这对于所提出的统计推断是至关重要的。建立Fre 'chet平均值存在的广泛条件，作为Fre' chet函数的唯一极小值，Q分布随机形状的期望平方距离对于统计推断很重要;这是该项目追求的目标，特别是对于内在分析，它从形状理论开始就一直是一个悬而未决的开放问题。由两幅（或多幅）航空照片重建一个场景是仿射形状分析的研究课题之一。投影形状分析的潜在应用包括人脸识别和机器人-机器人视觉识别scene.Statistical分析的几何对象，或流形上的数据，是一个令人兴奋和具有挑战性的研究领域，统计理论和微分几何是密不可分的交织在一起，实现需要创新的算法和高速计算。这里提出的项目涉及非参数方法在这方面的发展，这也必须解决相关的几何问题和实施问题。PI过去在这一领域取得的进展为本项目奠定了基础。所提出的统计分析具有广泛的应用，特别是在生物学和生物信息学、健康科学和机器视觉中。在该项目下，项目主管计划在理论和实际执行方面培训本科生和研究生，以及至少一名博士后研究员。这大大推进了方案执行机构目前在这方面的活动。此外，在网站上提供计算算法和代码，以创建和传播这项研究及其应用。