Performance Comparison of Fourier Transform and its Derivatives as Shape Descriptors for Mango Grading

Abstract

Mango is a tropical fruit of India which plays a major role in earning foreign currency by export. The export sector of India is paying attention towards it because of its commercial significance. Image has assorted inbuilt features which reflect its content such as color, texture, shape, and spatial relationship features, etc. How to organize and utilize these features effectively in agriculture era is a valuable research topic. Shape is a first quality factor to be considered by consumer while purchasing mango fruit. The purpose of this research work is to explore image processing algorithms and techniques to sort misshapen mango fruits based on their shape features. The developed algorithm would be first step in automated grading and sorting machines in export industries. It can provide a base for fully automatic grading system using computer vision. A shape based mango fruit sorting using computer vision is discussed in this paper. Shape features (Region based and contour based) are designed using Fourier Transform. Wavelet based descriptor is derived from basic Fourier transform to catch local shape details. A two layered radial basis neural network is developed to classify well formed and deformed mango fruits. The experiment results show performance comparison of all Fourier based shape descriptors. Wavelet Fourier Descriptor outperforms region based and contour based Fourier descriptor with classification efficiency of 89.83%.

Research on the Shape Classification Method of Rural Homesteads Based on Parcel Scale—Taking Yangdun Village as an Example

“…Fast Fourier transform (FFT) is simple and efficient, and it is one of the common methods to extract the boundary contour of an object [26,27]. Therefore, this study attempted to employ this method for the identification and classification of homestead boundaries.…”

Effective image models for inspecting profile flaws of car mirrors with applications

“…The primary thought of a Fourier descriptor is to utilize the Fourier transformed borders as the shape features. Khoje and Bodhe [17] compared classifi cation performance of the Fourier transform based shape descriptors and its derivatives for fruit quality grading of mangoes. Burla et al [18] developed two modifi ed Fourier descriptors methods for fast detection of surface defects on microlens arrays, one kind of micro-optical elements.…”

In-Line Sorting of Harumanis Mango Based on External Quality Using Visible Imaging

“…This process is usually done in the packing house, where the graders will judge the fruit shape base on the difference from the normal characteristic shape of the variety. Abnormality in shape mostly leads to rejection of foreign consignments [14]. Misshapen and malformation are the most common words to describe a product’s poor symmetry and abnormal concavities [15].…”

“…A fast and effective machine vision system is needed to grade the Harumanis mango. There are two main categories to characterize fruit shape which are size dependent measurements and size independent measurements [14]. Size-dependent measurements are a combination of size measurement features such as roundness, elongation, eccentricity and others.…”