Cultivar Identification of Lotus (Nelumbo nucifera Gaertn) by P-type Fourier Descriptors with Petal Tip Contour

Abstract

In this research, we quantitatively evaluated the shape of petal tips in lotus (Nelumbo nucifera Gaertn), using P-type Fourier descriptors. We developed a new program based on P-type Fourier descriptors to analyze the curves of petal tips from 7 varieties of lotus, which were extracted and described by Freeman chain codes. We then used principal component analysis to evaluate useful information to classify lotus cultivars in the coefficients of the P-type Fourier descriptors. 78% of the lotus cultivars could be identified from several principal components in Quadratic Discriminant Analysis (QDA) or Support Vector Machine (SVM) procedures programmed in R-language. The applications of the P-type Fourier descriptor can be extended to both open and closed curves.