The rapid advancements of digital technologies and the internet penetration, as well as the availability of digital cameras and smart-phones, have resulted in a great increase of multimedia data production worldwide. The amount of multimedia data available every day is enormous and is growing at an exponential rate. Therefore, there is a need for new and more efficient approaches for large scale multimedia search. In this context, this book will address the area of multimedia retrieval with a special emphasis on scalability. Specific topics will include: Concept and event-based video search in large collections; Multimedia retrieval models for big data; Approximate methods for big multimedia data retrieval; Domain adaptation for large scale multimedia search; Semantic search in large multimedia collections; Deep learning methods for large scale multimedia retrieval; Unsupervised and semi-supervised methods on big multimedia data; Large scale multimedia search based on multimodal fusion; Data-driven techniques for representation learning and classification on Big Data; Big data analysis on the web and social networks; Distributed solutions and architectures for big multimedia data analysis and retrieval; Big Media.