Effects of Context and Peripheral Viewing on Perception of Sharpness

This work investigates two visual phenomena known as: effect of context and peripheral sharpening overconstancy. The effect of context predicts an advantage for images that are familiar rather than images that are unusual. Rossel et al. (2022) investigated this latter phenomenon throughout three experiments consisting in adding blur to images and making participants judge which image appeared to them as the sharpest. The experiments in these thesis were modeled by the third experiment. In addition to familiarity, peripheral viewing it has also been manipulated. Images in the periphery appear sharper. This is known as peripheral sharpening overconstancy and it was firstly discovered by Galvin et al. (1997). The authors investigated the role of the peripheral vision in influencing images’ perception and found that the periphery generated an overconstancy upon images, making them appear sharper. The work in this thesis tested both of these variables: the effect of context and the peripheral sharpness overconstancy.Presentation was controlled by an EyeLink device. In agreement with Rossel et al. (2022) findings, data support the effect of context on image sharpness judgments. This is influenced by the peripheral sharpening that plays a role in modulating it.