  Augmented reality (AR) is one of the relatively old, yet trending areas in
the intersection of computer vision and computer graphics with numerous
applications in several areas, from gaming and entertainment, to education and
healthcare. Although it has been around for nearly fifty years, it has seen a
lot of interest by the research community in the recent years, mainly because
of the huge success of deep learning models for various computer vision and AR
applications, which made creating new generations of AR technologies possible.
This work tries to provide an overview of modern augmented reality, from both
application-level and technical perspective. We first give an overview of main
AR applications, grouped into more than ten categories. We then give an
overview of around 100 recent promising machine learning based works developed
for AR systems, such as deep learning works for AR shopping (clothing, makeup),
AR based image filters (such as Snapchat's lenses), AR animations, and more. In
the end we discuss about some of the current challenges in AR domain, and the
future directions in this area.
