Multiscale Fourier descriptors for defect image retrieval

Shape is an essential visual feature of an image and it is widely used to describe image content in image classification and retrieval. In this paper, two new Fourier-based approaches for contour-based shape description are presented. These approaches present Fourier descriptors in multiple scales, which improves the shape classification and retrieval accuracy. The proposed methods outperform ordinary Fourier descriptors in the retrieval of complicated shapes without increasing computational cost.