The SITIS conference is dedicated to research on the technologies used to represent, share and process information in various forms, ranging from signal, image, and multimedia data to traditional structured data and semi-structured data found in the web. SITIS spans two inter-related research domains that increasingly play a key role in connecting systems across network centric environments to allow distributed computing and information sharing. SITIS 2015 aims to provide a forum for high quality presentations on research activities centered on three main tracks. The track titled "Signal & Image Technologies" (SIT) focuses on recent developments in digital signal processing and pays particular attention to evolutions in audiovisual signal processing, analysis, coding and authentication, and retrieval techniques. The focus of the "Multimedia Information Retrieval and Application" (MIRA) is on emerging modeling, representation and retrieval techniques that take into account the amount, type and diversity of multimedia information accessible in distributed computing environment. The track titled "Web Computing and Applications" (WeCA) is on emerging and novel concepts, architectures and methodologies for information management, including the semantic web, big data, and cloud computing. SITIS is also dedicated to bring together scientists from the world over, particularly from developing countries, to share and exchange knowledge, experience and research results. When the conference is hosted by research institutions in developing countries, a particular emphasis will be placed on the presentation of applied research, the organization of practical tutorials and workshops that may help address the information processing needs of these countries, and book give away sessions to allow conference attendees to donate books to the local institutions.