The two volume set LNCS 4351 and LNCS 4352 constitutes the refereed proceedings of the 13th International Multimedia Modeling Conference, MMM 2007, held in Singapore in January 2007.Based on rigorous reviewing, the program committee selected 123 carefully revised full papers of the main technical sessions and 33 revised full papers of 4 special sessions from a total of 392 submissions for presentation in two volumes. The first volume includes 76 contributions related to learning semantic concepts, graphics, image registration, matching and texture, human-computer interaction, tracking and motion analysis, advanced media coding and adaptation, media annotation, image and video coding, context-aware media modeling, multimedia databases, media retrieval, P2P networks, semantic video concepts, audio and video coding, content, applications, computer vision, and image processing. The second volume collects 80 papers related to multimedia signal processing and communications, event detection, multimedia over P2P, content, applications, computer vision, image processing, multimedia signal processing and communications, image classification and recognition, advanced media processing and security, ubiquitous multimedia service (UMS), services and the assurance in multimedia mobile information systems (SAMM) , networked mulitmedia systems and its applications focusing on reliable and flexible delivery for integrated multimedia (NMS), and networked graphics appications (NGA).