Local multiple orientation estimation: isotropic and recursive oriented network

In this paper, we propose a new operator for texture orientation estimation. We focus on directional textures which can have more than a single orientation at the same point. Our operator consists in a steerable network of parallel lines along which a homogeneity feature is computed in the spatial domain. The analysis of the network response along each direction allows us to set up the presence of single or multiple orientations. In order to reduce the computing cost, we propose a recursive implementation of our operator, thanks to the rotations of the image instead of the rotation of the network. Our operator works on a small support, and thus provides a local estimation of the orientations. Results obtained both with synthetic textures and natural images are accurate and show the selectivity and the isotropic behaviour of our operator.