PATTERN RECOGNITION

Projectively invariant recognition of compound ovals

P. P. Nikolayev

Institute for Information Transmission Problems of the Russian Academy of Sciences (Kharkevich Institute), Moscow

Abstract: We consider the problem of projectively invariant recognition of ovals (smooth planar figures), but possessing, by virtue of the mechanism of their generation, smooth conjunctions of a few fragments, each of these being analytically described by a corresponding set of shape coefficients. We propose original methods for detecting the conjunction points of the segments, discuss their role in building either a global or a local invariant basis of the figure, which ensures its recognition, independent of perspective transformations of the oval on the sensor plane of the detecting optical system and depending on the chosen angle of view (within the approximation of a central planar projection).

Keywords: oval, projective transformation, quadratic form, wurf, tangent, projectively invariant mapping, conjunction point.