Measurement Covariance Structure for Pseudo Landmarks
نویسندگان
چکیده
In previous documents we have outlined an approach for the analysis of 2 and 3D shape vectors using measurement covariances for the situation where the measurements are known to be independent. The purpose of this document is to explain the mathematics required to extend this approach to “pseudolandmarks”, where information is provided at a given 2 or 3D location only in 1D. We show that the use of a pseudo-inverse together with generalisation of the measurement process is sufficient to solve the task.
منابع مشابه
Morphometric Shape Analysis with Measurement Covariance Estimates
We propose a shape analysis system based upon the description of landmarks with measurement covariance, which extends statistical linear modelling processes to ‘pseudo landmarks’ for scientific studies. We discuss the properties of our approach and how measurement covariances can be considered characteristic of the local shape. Our formulation includes corrections for parameter bias, induced by...
متن کاملMeasurement-Based Shape Analysis
Conventional methods for shape analysis, based upon Procrustes and PCA, seem incapable of dealing with ‘non-landmark’ features, meaning measured positions not associated with well defined locations. This is due to an assumption of homogeneous errors, associated with an attempt to extract linear models with biologically meaningful descriptions. We propose a shape analysis system based upon the d...
متن کاملShape Analysis using Measurement Covariances
Conventional methods for shape analysis, based upon Procrustes and PCA, seem incapable of dealing with ‘non-landmark’ features, meaning measured locations not associated with well defined locations. We argue here that this is due to an assumption of homogenous errors, associated with an attempt to extract linear models with biologically meaningful descriptions. This document contains the mathem...
متن کاملFuzzy Landmark Detection in Simultaneous Localisation and Mapping for Agricultural Robots
This paper deals with the problem of landmark detection for application of Simultaneous Localization and Mapping (SLAM) for agricultural robots. A new method of using a fuzzy rule base for fast evaluation of landmarks based on its measurement error, amount of dynamic nature, need for a landmark and evaluation time has been proposed. The output of the fuzzy system is a multiplier which represent...
متن کاملمقایسه تفاوت لندمارک های آناتومیک دو تکنیک رادیوگرافی لترال سفالومتری دیجیتال و معمولی به روش ترسیم دستی در جمجمه های انسانی
Background and purpose: Digital radiography has led to many improvements in radiology. Despite many advantages there are different ideas in determining anatomical landmarks which results in some errors in cephalometric analyses. The aim of this study was to determine the degree of identification differences of anatomical landmarks by conventional and digital lateral cephalometric techniques usi...
متن کامل