EventMask: A Game-Based Framework for Event-Saliency Identification in Images

The concept of "event" emerged in recent years as a key feature to efficiently index and retrieve media. Several approaches have been proposed to analyze the relationship between events and media, enable event discovery, and perform event-based media tagging, indexing, and retrieval. Despite the outstanding work done in this area, a major problem that remains open is how to infer the link between visual concepts and events. In particular, the possibility of understanding which perceptual elements allow a human recognizing the event depicted by an image would open new directions in event media discovery. In this paper we introduce the concept of event saliency to define the above event-revealing perceptual elements, and we propose an original method to detect it by exploiting crowd knowledge through gamification. We propose an adversarial game with a hidden purpose, where users are engaged in competitive roles: masking photos to prevent competitors recognizing the related event, and dis...