FIELD-OF-VIEW EFFECT ON THE PERCEIVED QUALITY OF OMNIDIRECTIONAL IMAGES

To visualize omnidirectional (or 360°) visual content, the rectilinear
perspective projection is commonly employed to map the visual
information from the observed area (or viewport) of the viewing
sphere to a plane, resulting in the viewport image that is shown to
the user. To enhance the user sense of immersion and engagement
when exploring the 360° visual content, the viewport field of view
(FoV) should be large; however, large FoVs introduce geometric
distortions (e.g., objects stretching and shearing); thus, the FoV has
an important role on the user’s quality of experience (QoE). In this
paper, a subjective test campaign was conducted, aiming to assess
the FoV effect on perceived quality and to find the FoV that presents
the best trade-off between user immersive experience and perceived
geometric distortions. The analysis of the subjective test results
shows that a FoV close to 110° has the highest preference among the
observers who participated in the test.