2000 Volume 20 Issue 2 Pages 131-141
A method for quantitative evaluation of 3-dimensional (3D) fruit morphology was proposed, including measurement, quantitative description, normalization and statistical analysis of the 3D fruit shape. A measurement system consisting of a CCD laser displacement sensor and two pulse stages was constructed to obtain 3D surface data of fruit. By expanding the shape data measured in a series of spherical harmonic functions, a collection of coefficients to characterize the object surface were obtained. The surface data and coefficients expanded were normalized to provide viewpoint independent of object coordinates for comparison and analysis of different fruits. Based on the principal component analysis about the normalized spherical harmonic coefficients, the scores of some first principal components with high contributions were chosen to summarize the information about 3D shape. We applied the method to evaluate the genetic behavior for citrus and persimmon varieties.
