  The acorn is the fruit of the oak and is an important crop in the Spanish
dehesa extreme\~na, especially for the value it provides in the Iberian pig
food to obtain the "acorn" certification. For this reason, we want to maximise
the production of Iberian pigs with the appropriate weight. Hence the need to
know the area covered by the crowns of the acorn trees, to determine the
covered wooded area (CWA, from the Spanish Superficie Arbolada Cubierta SAC)
and thereby estimate the number of Iberian pigs that can be released per
hectare, as indicated by the royal decree 4/2014. In this work, we propose the
automatic estimation of the CWA, through aerial digital images (orthophotos) of
the pastureland of Extremadura, and with this, to offer the possibility of
determining the number of Iberian pigs to be released in a specific plot of
land. Among the main issues for automatic detection are, first, the correct
identification of acorn trees, secondly, correctly discriminating the shades of
the acorn trees and, finally, detect the arbuscles (young acorn trees not yet
productive, or shrubs that are not oaks). These difficulties represent a real
challenge, both for the automatic segmentation process and for manual
segmentation. In this work, the proposed method for automatic segmentation is
based on the clustering algorithm proposed by Gustafson-Kessel (GK) but the
modified version of Babuska (GK-B) and on the use of real orthophotos. The
obtained results are promising both in their comparison with the real images
and when compared with the images segmented by hand. The whole set of
orthophotos used in this work correspond to an approximate area of 142
hectares, and the results are of great interest to producers of certified
"acorn" pork.
