This book constitutes the refereed proceedings of CVM 2025, the 13th International Conference on Computational Visual Media, held in Hong Kong SAR, China, in April 2025. The 67 full papers were carefully reviewed and selected from 335 submissions. The papers are organized in topical sections as follows: Part I: Medical Image Analysis, Detection and Recognition, Image Enhancement and Generation, Vision Modeling in Complex Scenarios Part II: 3D Geometry and Rendering, Generation and Editing, Image Processing and Optimization Part III: Image and Video Analysis, Multimodal Learning, Geometrical Processing, Applications.