This book contains new research works presented at the Fourth World Conference on Intelligent and 3D Technologies (WCI3DT 2025), organized by IRNet International Academic Communication Center, held in Shanghai, China during May 23 – 25, 2025. The main topics in this volume cover contemporary parts in the multidimensional signal processing, based on deep learning and related applications. Special attention is given to neural networks, which make up the backbone of deep learning algorithms and their improvement, and research works aimed at the real-time interaction with unmanned vehicles, machine translation, cloud computing, personalized product recommendation model for autonomous robots, power production monitoring and control, optimization and acceleration of machine learning algorithms, pattern recognition, building crack detection and many others.