*2.4.1 State of the art*

Many of the tasks, such as video analysis, text mining or case-based reasoning, are very compute and data intensive. Processing large amounts of multimedia data for police investigation purposes must take into account scalability and performance requirements in order to be usable in a professional context. Cloud computing [46] has emerged as a good model for providing compute and storage resources on demand. To benefit from these available resources, applications that are deployed in the cloud need to be designed to scale and to be able to benefit from parallel processing of data with approaches such as map-reduce [47].
