Coffee leaf rust disease detection using MobileNetV2-based feature extractor, SVM classifier and visualization technique

The coffee plant is a vital crop, particularly in Vietnam, and is vulnerable to weather, cultivation methods, and diseases like rust disease. Early detection and treatment of rust disease are essential to ensuring coffee yield and quality. This study introduces a hybrid model for automated rust disease detection from coffee leaf images. The approach employs MobileNetV2 for feature extraction using convolutional neural networks (CNNs) and a Support Vector Machine (SVM) for classification. Experiments also evaluated other lightweight CNNs like MobileNet and NASNetMobile, as well as classifiers like DecisionTree and RandomForest, but MobileNetV2 and SVM delivered optimal results. The model was trained on the publicly available RoCoLe dataset and achieved a rust disease detection accuracy of 97.13%, surpassing standard CNN approaches by 2.39%. Additionally, the study uses Grad-CAM to visualize key areas in coffee leaf images that influence the classification process, offering insights into how the model distinguishes between healthy and diseased leaves. This methodology supports early disease detection and provides tools for understanding the model's decision-making process, contributing to more effective coffee plant disease management.