A Symmetry-Aware Shape Descriptor Framework for Automated Defect Detection in Chocolate Images using Geometric Feature Engineering
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How to Cite

Benjamin, Ruth Moly, Abraham Chandy D., and Hepzibah Christinal A. 2026. “A Symmetry-Aware Shape Descriptor Framework for Automated Defect Detection in Chocolate Images Using Geometric Feature Engineering”. Journal of Trends in Computer Science and Smart Technology 8 (3): 728-44. https://doi.org/10.36548/jtcsst.2026.3.015.

Keywords

Chocolate Defect Detection
Shape Analysis
Symmetry-Aware Descriptors
Support Vector Machine (SVM)
Image Processing
Quality Inspection
Geometric Features

Abstract

In recent years, developments in food quality and safety regulations have placed greater importance on high-quality food production. Foods that are inspected for quality defects include chocolates that are susceptible to defects during their manufacturing process. Currently, there are various techniques for detecting defects in chocolates, but most focus on global properties of the shape of chocolates. In this study, a new technique called Symmetry Aware Shape Descriptor (SASD) approach was proposed for automatic defect detection in chocolates. This algorithm is composed of two descriptors; Symmetry Difference Index (SDI), which measures the global symmetry properties of a shape, and Symmetry Residual Descriptor (SRD), which measures the local asymmetry properties of the shape. After the extraction of these two descriptors, they form a feature vector, which is then classified using Support Vector Machine (SVM) Classifier. To perform a comparative analysis, classical shape-based approaches, basic shape features, Hu moments, and convex hull-based approaches were also implemented. The dataset used in this study consists of 225 chocolate images from 14 different chocolate brands. The suggested framework exhibited improved performance when compared to conventional methods, where the classification accuracy and precision achieved by this framework were 77.78% and 78.95%, respectively. These results show that the suggested SASD framework is an effective, transparent, and computationally efficient method for automated defect detection in chocolates.

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