Analysis of Error Factors in Estimation of Anatomical Landmarks from 3D Foot Model using Free-Form Deformation

In order to design industrial products fitting well to the human body, it is necessary to make full use of information of human anatomical landmarks. These landmarks however cannot be extracted automatically from point cloud data of human body surface obtained by a 3D scanner. In our previous report, we proposed the method of extracting the landmarks automatically by deforming the template of point cloud form data with known landmark positions using Free Form Deformation (FFD) method. In this method, it is possible to estimate positions of the landmark by deforming the template model with the anatomical feature retained. However, estimation error in the method was more than permissible amount. This paper discusses an analysis of the factors of estimation error, and proposes revised method of reduced estimated errors for landmarks around the ankle.