João F. P. Crespo

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When comparing 2-D shapes, a key issue is their normalization. Translation and scale are easily taken care of by removing the mean and normalizing the energy. However, defining and computing the orientation of a 2-D shape is not so simple. In fact, although for elongated shapes the principal axis can be used to define one of two possible orientations, there(More)
The analytic signature is a recently proposed 2D shape representation scheme. It is tailored to the representation of shapes described by arbitrary sets of unlabeled points, or landmarks, because its most distinctive feature is the maximal invariance to a permutation of those points. The shape similarity of two point clouds can then be obtained from a(More)
There is an ever-increasing demand for high quality forage legumes, essential to feed livestock. Micropropagation may be useful to preserve elite allelic compositions in allogamous and auto-incompatible forage legume species, as is the case of Trifolium resupinatum L. (Persian clover). Etiolation-like phenotypes in in vitro cultured plants, with long weak(More)
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