Free-viewpoint television (FTV) and virtual navigation appear to be hot research topics. In this paper, the authors study the practical development of free-viewpoint television systems that provide the functionality of virtual horizontal navigation around real scenes. The considerations are focused on practical systems that use purely optical depth estimation and might be employed in the next few years. The architectures of such systems are discussed in detail, including acquisition, preprocessing, depth estimation, compression, and presentation. In particular, the optimization of camera locations is discussed, and it is shown that video acquisition using camera pairs is advantageous for scenes with a substantial amount of occlusions. The theoretical considerations are supported by experimental results obtained for standard test multiview video sequences. Furthermore, the paper describes FTV video acquisition systems that consist of modules with pairs of cameras. The modules are sparsely located in arbitrary positions around a scene. Each camera module is equivalent to a video camera with a depth sensor. The hardware requirements, video processing algorithms, and experimental results are reported. In particular, for such systems, a compression technique is discussed that is more efficient than the new three-dimensional HEVC technology. The paper also describes new test video sequences that are obtained from the camera pairs sparsely distributed around scenes.

The paper presents the concept of a practical free-viewpoint television system with purely optical depth estimation. The system consists of camera modules that contain pairs or triples of cameras together with the respective microphones. The camera modules can be sparsely located in arbitrary positions around a scene. Each camera module is equivalent to a video camera with a depth sensor and microphones. The hardware requirements, the video and audio processing algorithms and the preliminary experimental results are reported. In particular, for such systems, a compression technique is discussed that is more efficient than the new 3D-HEVC technology. A set of new test sequences obtained with the use of camera pairs are presented.