Efficient Image Indexing and Retrieval over Mobile Devices

The multimedia capabilities of mobile phones are rapidly increasing in recent years. It is now common that users can send and retrieve images over mobile phones. Image searching and retrieval is fundamentally becoming an important operation and yet there isn't any efficient and effective way to do this over mobile phones. The situation is particularly more acute when users attempt to access a content provider with a large collection of image contents. Any aimless browsing of the images will translate into air-time costs. Therefore, an efficient and effective mechanism to retrieve images over mobile phones must be sought. In this paper, we attempt to advance this area of mobile multimedia by providing a data model as well as a query model for searching images efficiently and effectively. The data model is a semantically rich structure for representing any salient features in the image contents. XML Schema is used to model the data structure and a number of examples are illustrated in this paper. The query model works intimately with the data model and it goes beyond simple Boolean type queries. The query model supports ranked queries from the repository of image contents. The most precisely matched images will be delivered first. Users can browse the ranked images through the logical expression of the query over mobile phones. The system architecture to support the indexing and retrieval of images in our data and query model over mobile devices is described. As the popularity of micro-browsers on mobile phones capable of retrieving XTHML-MP pages over WAP gateways increase, it provides an ideal opportunity for us. We can bridge the wireless world with the Internet world seamlessly. A simulation of the concepts using XTHML-MP with WAP 2.0 is provided.