  Multiview applications endow final users with the possibility to freely
navigate within 3D scenes with minimum-delay. A real feeling of scene
navigation is enabled by transmitting multiple high-quality camera views, which
can be used to synthesize additional virtual views to offer a smooth
navigation. However, when network resources are limited, not all camera views
can be sent at high quality. It is therefore important, yet challenging, to
find the right tradeoff between coding artifacts (reducing the quality of
camera views) and virtual synthesis artifacts (reducing the number of camera
views sent to users). To this aim, we propose an optimal transmission strategy
for interactive multiview HTTP adaptive streaming (HAS). We propose a problem
formulation to select the optimal set of camera views that the client requests
for downloading, such that the navigation quality experienced by the user is
optimized while the bandwidth constraints are satisfied. We show that our
optimization problem is NP-hard, and we therefore develop an optimal solution
based on the dynamic programming algorithm with polynomial time complexity. To
further simplify the deployment, we present a suboptimal greedy algorithm with
effective performance and lower complexity. The proposed controller is
evaluated in theoretical and realistic settings characterized by realistic
network statistics estimation, buffer management and server-side representation
optimization. Simulation results show significant improvement in terms of
navigation quality compared with alternative baseline multiview adaptation
logic solutions.
