Growth ring detection on fish otoliths by a graph construction

We present an algorithm for the detection of fish otolith growth rings based on a graph construction method. The identification of growth rings, for age estimation, is routinely achieved in fishery laboratories by human readers. One of the major problem encountered during an automatic image processing is the lack of ring continuity perception. We present an approach to this continuity perception based on the 2D reconstruction of rings from the restoration of the connectivity of nodes detected in polar coordinates. The node connection is based on an a priori knowledge of ring geometry