@InProceedings{kita:icpr:2016,
  author       = {Kita, Yasuyo and Kita, Nobuyuki},
  title        = {Virtual Flattening of Clothing Item Held in the Air},
  booktitle    = {IAPR/IEEE International Conference on Pattern Recognition},
  year         = {2016},
  volume       = {25},
  pages        = {2771--2777},
  address      = {Cancun, Mexico},
  month        = {December\textasciitilde 04--08},
  organization = {International Association of Pattern Recognition},
  url          = {https://staff.aist.go.jp/y.kita/Papers/ICPR16\_virtual.pdf},
  keywords     = {Clothing, Three-dimensional displays, Shape, Mathematical model, Springs, Robots, Two dimensional displays},
  doi          = {10.1109/ICPR.2016.7900055},
  abstract     = {We propose a method of virtually flattening the surface of a clothing item to a two-dimensional plane using the geodesic distance over the surface of the item. If a clothing item is flatly opened on a table, the recognition of the item is much easier than that of the same item having an arbitrary shape. However, it is difficult and troublesome to physically flatten a clothing item from its arbitrary shape automatically. We therefore propose to develop the surface of the clothing item held in the air into a two-dimensional shape using three-dimensional observation data of the surface. To this end, boundary points of the observed clothing region are sampled as start/end nodes for calculating geodesic lines, the lengths of which become two-dimensional distances between the points when the surface is flattened to a plane. To robustly calculate geodesic lines using a three-dimensional point cloud of the surface, we adopt a method that interpolates the depth and normal direction at any point on the surface using the element-free Galerkin method. The shortest path along the surface between two points on the surface is then calculated using these depths and normal directions in the framework of the \textquotedblleft zero-length spring analogy\textquotedblright . The two-dimensional coordinates of the points on the plane are obtained by solving simultaneous equations determined by the geodesic distances. We also propose a method of using the flattened view for the classification of clothing type and detection of important parts of clothing. Preliminary experiments using long-sleeve shirts and trousers as clothing items demonstrate the promise of the proposed methods.}
}