  Deep learning (DL) has seen great success in the computer vision (CV) field,
and related techniques have been used in security, healthcare, remote sensing,
and many other fields. As a parallel development, visual data has become
universal in daily life, easily generated by ubiquitous low-cost cameras.
Therefore, exploring DL-based CV may yield useful information about objects,
such as their number, locations, distribution, motion, etc. Intuitively,
DL-based CV can also facilitate and improve the designs of wireless
communications, especially in dynamic network scenarios. However, so far, such
work is rare in the literature. The primary purpose of this article, then, is
to introduce ideas about applying DL-based CV in wireless communications to
bring some novel degrees of freedom to both theoretical research and
engineering applications. To illustrate how DL-based CV can be applied in
wireless communications, an example of using a DL-based CV with a
millimeter-wave (mmWave) system is given to realize optimal mmWave
multiple-input and multiple-output (MIMO) beamforming in mobile scenarios. In
this example, we propose a framework to predict future beam indices from
previously observed beam indices and images of street views using ResNet,
3-dimensional ResNext, and a long short-term memory network. The experimental
results show that our frameworks achieve much higher accuracy than the baseline
method, and that visual data can significantly improve the performance of the
MIMO beamforming system. Finally, we discuss the opportunities and challenges
of applying DL-based CV in wireless communications.
