A. Formella, J.M. Vzquez, P. Carrin, E. Cernadas, A. Vzquez, and G. Prez-Gndaras (Spain)
otolith reading, image morphing, fourier analysis.
We present a semi–automatic system that detects and
counts the yearly growths rings of cod otoliths. The system
is based on morphing an angular section of the otolith to a
rectangular region where the vertical directions follow B–
splines that we place with an optimization algorithm such
that they cross the rings in a close to perpendicular man
ner. The rectangular area is treated with standard Fourier
techniques and classical ﬁlters. We obtain a large number
of intensity proﬁles which we further analyze to count the
annual rings. The preliminary results achieved on a small
subset of our large database are encouraging. The manual
steps of the system are easy to be performed automatically
as well, however, we postponed their implementation con
centrating at the beginning on the global system design.