The three-volume set LNCS 16507, 16508 and 16509 constitutes the refereed proceedings from the 42nd Computer Graphics International Conference, CGI 2025, held in Hong Kong, China, during July 14&18, 2025. The 124 full papers presented in these proceedings were carefully reviewed and selected from 402 submissions. The papers are organized in the following topical sections: Part I: Colors, Painting and Layout; Graphics and VR/AR; Medical Imaging and Robotics; Segmentation and Understanding; and Visual Analytics and Modeling. Part II: Detection and Recognition; Image Analysis and Processing; Image Attention and Perception; Reconstruction; and Rendering and Animation. Part III: Image Analysis and Visualization; Image Restoration and Enhancement; Super-Resolution and Recovery; Synthesis and Generation; and Theoretical Analysis.