Effectively and efficiently retrieving information based on user needs is one of the most exciting areas in multimedia research. The Annual ACM International Conference on Multimedia Retrieval (ICMR) offers a great opportunity for exchanging leading-edge multimedia retrieval ideas among researchers, practitioners and other potential users of multimedia retrieval systems. This annual conference, which puts together the long-lasting experiences of the former ACM CIVR (International Conference on Image and Video Retrieval) and ACM MIR (International Conference on Multimedia Information Retrieval) series, was set up in 2011 to illuminate the state of the arts in multimedia (e.g., text, image, video, audio, sensor data, 3D) retrieval.