<p>To whom it may concern,</p><p>In this
paper, we provide an in-depth and comprehensive survey on recent technical
advancements in deep learning for omnidirectional vision, and also provide new
perspectives for the future direction.<br></p><p><br></p><p>Deep learning (DL) has recently been applied to omnidirectional vision.
DL-based omnidirectional vision methods often achieve the state-of-the-art
(SoTA) performance on various benchmark datasets. Diverse deep neural network
(DNN) models have been developed, ranging from the convolutions neural network
(CNN)-based models to vision transformers (ViT)-based ones. Generally, the SoTA
DNN-based methods differ from each other in four major aspects: convolutional
filters used to extract features from the omnidirectional image (ODI) data, network
design considering the input numbers and projection types, omnidirectional
vision with novel learning strategies, and practical applications.<br></p><p><br></p><p>In this paper, we provide a comprehensive and systematic review and
analysis of the recent progress in DL methods for omnidirectional vision. There
are some previous surveys in the literature. However, some of them are focused
on the specific vision tasks, especially room layout reconstruction, 3D scene
geometry recovery. Moreover, some provide limited reviews of omnidirectional
video streaming methods. <i>Unlike existing
surveys, this paper highlights the importance of deep learning and probe the
recent advances for omnidirectional vision, both methodically and
comprehensively. To the best of our knowledge, this is the <b>first</b> survey to comprehensively review and analyze the DL methods
for omnidirectional vision.</i><br></p><p><i><br></i></p><p></p><p>The main contributions
of this paper to the community are five folds: </p>
<p>(I)
We
comprehensively review and analyze the DL methods for omnidirectional vision,
including the omnidirectional imaging principle, representation learning,
datasets, a taxonomy, and applications, to highlight the differences and
difficulties with the 2D planner image data.</p>
<p>(II)
We
conduct an analytical study of recent trends of DL for omnidirectional vision,
both hierarchically and structurally. Moreover, we offer insights into the
discussion and challenge of each category. </p>
<p>(III)
We
summarize the latest novel learning strategies and potential applications for
omnidirectional vision.</p><p>(I)
We
provide insightful discussions of the challenges and open problems yet to be
solved and propose the potential future directions to spur more in-depth
research by the community.</p><i></i><p></p><p>(II)
We
create an open-source repository that provides a taxonomy of all the mentioned
works and code links, and hope it can shed light on future research.</p><p>
</p><p>The organization of this
paper is structured as follows. In Sec.2, we introduce the imaging principle of
ODI, convolution methods for omnidirectional vision, and some representative
datasets. In Sec.3, we review and analyze the existing DL approaches for
various tasks and provide taxonomies to categorize the relevant papers. Sec.4 covers
novel learning paradigms for the tasks in omnidirectional vision, e.g.,
unsupervised learning, transfer learning, and reinforcement learning. Sec.5 then
scrutinizes the applications, followed by Sec. 6, where we
discuss open problems and future directions. Finally, we conclude
this paper in Sec. 7. Furthermore, we summarize most, if not all but representative,
works (over 200 papers) in the last five years, which were published in the top-tier
conferences and journals in computer vision/graphics and machine learning. <i>Due to the lack of space, we show the
experimental results in Sec. 2 of the suppl. material.</i></p><p><i><br></i></p><p>We believe that this paper will bring significant interest in such
crucial topics in the community and provide fundamental technical references
for further research. <i><br></i></p>