  The growing interest in omnidirectional videos (ODVs) that capture the full
field-of-view (FOV) has gained 360-degree saliency prediction importance in
computer vision. However, predicting where humans look in 360-degree scenes
presents unique challenges, including spherical distortion, high resolution,
and limited labelled data. We propose a novel vision-transformer-based model
for omnidirectional videos named SalViT360 that leverages tangent image
representations. We introduce a spherical geometry-aware spatiotemporal
self-attention mechanism that is capable of effective omnidirectional video
understanding. Furthermore, we present a consistency-based unsupervised
regularization term for projection-based 360-degree dense-prediction models to
reduce artefacts in the predictions that occur after inverse projection. Our
approach is the first to employ tangent images for omnidirectional saliency
prediction, and our experimental results on three ODV saliency datasets
demonstrate its effectiveness compared to the state-of-the-art.
