Establishing reference scales for scene naturalness and openness : Naturalness and openness scales.

A key question in the field of scene perception is what information people use when making decisions about images of scenes. A significant body of evidence has indicated the importance of global properties of a scene image. Ideally, well-controlled, real-world images would be used to examine the influence of these properties on perception. Unfortunately, real-world images are generally complex and impractical to control. In the current research, we elicit ratings of naturalness and openness from a large number of subjects using Amazon Mechanic Turk. Subjects were asked to indicate which of a randomly chosen pair of scene images was more representative of a global property. A score and rank for each image was then estimated based on those comparisons using the Bradley-Terry-Luce model. These ranked images offer the opportunity to exercise control over the global scene properties in stimulus set drawn from complex real-world images. This will allow a deeper exploration of the relationship between global scene properties and behavioral and neural responses.