Depth Sensing for 3DTV: A Survey
---
paper_title: 3-D Video Representation Using Depth Maps

paper_content:

Current 3-D video (3DV) technology is based on stereo systems. These systems use stereo video coding for pictures delivered by two input cameras. Typically, such stereo systems only reproduce these two camera views at the receiver and stereoscopic displays for multiple viewers require wearing special 3-D glasses. On the other hand, emerging autostereoscopic multiview displays emit a large numbers of views to enable 3-D viewing for multiple users without requiring 3-D glasses. For representing a large number of views, a multiview extension of stereo video coding is used, typically requiring a bit rate that is proportional to the number of views. However, since the quality improvement of multiview displays will be governed by an increase of emitted views, a format is needed that allows the generation of arbitrary numbers of views with the transmission bit rate being constant. Such a format is the combination of video signals and associated depth maps. The depth maps provide disparities associated with every sample of the video signal that can be used to render arbitrary numbers of additional views via view synthesis. This paper describes efficient coding methods for video and depth data. For the generation of views, synthesis methods are presented, which mitigate errors from depth estimation and coding.
---
paper_title: 3D capturing using multi-camera rigs, real-time depth estimation and depth-based content creation for multi-view and light-field auto-stereoscopic displays

paper_content:

The wide variety of commercially available and emerging 3D displays - such as stereoscopic, multi-view and light-field displays - makes content creation challenging as each displays technology requires a different number of views available of the scene. As consequence, the content creation pipelines differ considerably and involve different camera setups such as beam-splitter rigs with small baselines and high quality cameras used for stereo 3D productions or camera arrays for auto-stereoscopic displays which usually use small lower quality cameras in a side-by-side arrangement. Converting content shot for a specific display technology into a different format usually impairs the image quality and is very labor-intensive.
---
paper_title: Microsoft Kinect Sensor and Its Effect

paper_content:

Recent advances in 3D depth cameras such as Microsoft Kinect sensors (www.xbox.com/en-US/kinect) have created many opportunities for multimedia computing. The Kinect sensor lets the computer directly sense the third dimension (depth) of the players and the environment. It also understands when users talk, knows who they are when they walk up to it, and can interpret their movements and translate them into a format that developers can use to build new experiences. While the Kinect sensor incorporates several advanced sensing hardware, this article focuses on the vision aspect of the Kinect sensor and its impact beyond the gaming industry.
---
paper_title: Solid-state time-of-flight range camera

paper_content:

The concept of a real-time range camera without moving parts is described, based on the time-of-flight (TOF) principle. It operates with modulated visible and near-infrared radiation, which is detected and demodulated simultaneously by a 2-D array of lock-in pixels employing the charge-coupled device principle. Each pixel individually measures the amplitude, offset and phase of the received radiation. The theoretical resolution limit of this TOF range camera is derived, which depends on the square root of the detected background radiation and the inverse of the modulation amplitude. Actual measurements of 3-D sequences acquired at 10 range images per second show excellent agreement between our theory and the observed results. A range resolution of a few centimeters over a range of 10 m, with an illumination power of a few hundreds of milliwatts is obtained in laboratory scenes for noncooperative, diffusely reflecting objects.
---

Title: Depth Sensing for 3DTV: A Survey

Section 1: Introduction
Description 1: Provide an introduction to depth sensing in 3DTV, explaining the transition from stereoscopic 3D to autostereoscopic multiview displays, and the importance of depth-information acquisition.

Section 2: Passive Stereovision Analysis
Description 2: Explain the concept of passive stereovision analysis, its advantages and challenges, and how it is used to generate depth maps directly from multiview videos.

Section 3: Active Stereovision Analysis
Description 3: Describe active stereovision analysis, how it combines an active light source with cameras, its advantages over passive stereovision, and its limitations.

Section 4: Depth from Dedicated Sensors
Description 4: Detail the use of dedicated time-of-flight (ToF) sensors, the different types of ToF sensors, their accuracy, and their suitability for real-time 3DTV content creation.

Section 5: Comparison and Conclusion
Description 5: Summarize the characteristics of each depth-sensing approach, comparing their flexibility, real-time capabilities, and environmental limitations, and provide insights into future trends in depth sensing for 3DTV.