Camera-enabled mobile devices are commonly used as interaction platforms for linking the user's virtual and physical worlds in numerous research and commercial applications, such as serving an augmented reality interface for mobile information retrieval. The various application scenarios give rise to a key technique of daily life visual object recognition. On-premise signs (OPSs), a popular form of commercial advertising, are widely used in our living life. The OPSs often exhibit great visual diversity (e.g., appearing in arbitrary size), accompanied with complex environmental conditions (e.g., foreground and background clutter). Observing that such real-world characteristics are lacking in most of the existing image data sets, in this paper, we first proposed an OPS data set, namely OPS-62, in which totally 4649 OPS images of 62 different businesses are collected from Google's Street View. Further, for addressing the problem of real-world OPS learning and recognition, we developed a probabilistic framework based on the distributional clustering, in which we proposed to exploit the distributional information of each visual feature (the distribution of its associated OPS labels) as a reliable selection criterion for building discriminative OPS models. Experiments on the OPS-62 data set demonstrated the outperformance of our approach over the state-of-the-art probabilistic latent semantic analysis models for more accurate recognitions and less false alarms, with a significant 151.28% relative improvement in the average recognition rate. Meanwhile, our approach is simple, linear, and can be executed in a parallel fashion, making it practical and scalable for large-scale multimedia applications.

We propose MobileQueue, a mobile queue-card management system that offers more freedom to customers by enabling image-based queue-card retrieving and service-information querying actions using mobile phones. MobileQueue interacts with cloud services allowing customers to query summary description and availability (e.g., available seats) of services provided by stores. MobileQueue also offers suggestions to waiting customers such as potentially interesting substitute activities and stores.

Narrative video analysis has attracted much research attention, for narrative scenes can provide meaningful representations of multimedia contents. To go beyond the limitations of content based appraoches, social network techniques was introduced in the literature to explore the high-level narrative structures by mining the relations between video characters. Taking into account the fact that such a social network is not static but changes over time as the video narrative evolves, in this work, we develop a novel social network model, namely dynamic social network, for capturing the spatiotemporal dynamics in the social network of video characters so as to enable the automatic segmentation of a video into a sequence of narrative scenes. The proposed approach is experimented with various genres of movies and the results demonstrate our effectiveness.