The document discusses using image processing and machine learning techniques like convolutional neural networks (CNNs) to detect plant leaf diseases. It proposes a system that uses CNNs to classify plant leaf images and detect diseases. The system would first preprocess leaf images, then extract features from them and feed them into a CNN model for classification. This could help farmers detect diseases early and improve crop productivity. The document reviews several related works applying CNNs and deep learning to tasks like mango leaf disease detection, tomato disease detection, and dragon fruit maturity detection with high accuracy. It outlines the proposed system architecture and algorithm and concludes CNNs can accurately detect plant diseases with reduced time and cost compared to manual methods.