Decomposition of nD-rotations: Classification, properties and algorithm

International audienceIn this paper, the decomposition of nD-rotations is studied. Using this decomposition, nD-rotations are classified and properties are underlined. A generalization of the algorithm previously presented by the authors to decompose nD-rotation into planar rotations is proposed. Since our framework includes experimental applications, we designed a method that is somewhat robust to noise. An alternate algorithm based on the Schur decomposition is investigated. A comparison between both methods is finally provided

3D discrete rotations using hinge angles

International audienceIn this paper, we study 3D rotations on grid points computed by using only integers. For that purpose, we investigate the intersection between the 3D half-grid and the rotation plane. From this intersection, we define 3D hinge angles which determine a transit of a grid point from a voxel to its adjacent voxel during the rotation. Then, we give a method to sort all 3D hinge angles with integer computations. The study of 3D hinge angles allows us to design a 3D discrete rotation and to estimate the rotation between a pair of digital images in correspondence