The two-volume set LNCS 9279 and 9280 includes the peer-reviewed proceedings of the 18th International Conference on Image Analysis and Processing, ICIAP 2015, which took place in September 2015 in Genoa, Italy. Out of 231 submitted papers, 129 were carefully selected and reviewed. The contributions are organized into seven thematic sections that address various aspects of image analysis and processing. These include, among others, video analysis and understanding, multiview geometry and 3D computer vision, pattern recognition and machine learning, as well as applications in biomedicine. This work provides a comprehensive overview of current research findings and developments in these fields and is aimed at professionals and students engaged with the latest advancements in image processing technology.