AN ASSESSMENT OF 3DTV TECHNOLOGIES

Stereoscopic 3D viewing techniques are almost as old as their 2D counterparts: experimental stereoscopic 3DTV immediately followed the invention of TV. Holography is a newer technology compared to stereoscopy, and there are indicators that satisfactory holographic 3DTV may be feasible. Another candidate technology for 3DTV is integral imaging. Holography and integral imaging provide true full parallax 3D displays in the ideal case. All these technologies have their own distinct features, advantages and problems. Interest in all forms of 3DTV has been significantly increasing both in research and commercial communities. An integrated 3DTV system naturally has different components: capturing of 3D moving scenes, their representation, compression and transport, and finally display are the main building blocks. Naturally, the consumer attitude and the related social issues will be rather centred around the display and interaction. 3D scenes can be captured by various means, for example, by using many cameras simultaneously. Furthermore, it is desirable to serve all types of 3D displays with different capabilities. Therefore, It is envisaged that scene capture and display operation will be decoupled in future 3DTV systems: captured scene information will be converted to abstract representations (and maybe stored) using computer graphics techniques, and the display (and observer) will interact with this intermediate data. It is natural to extend conventional video compression techniques to 3D video signals by exploiting the inherent redundancies. Coding of 3D video signals is attracting research interest and related standardization activities are ongoing in bodies like ISO-MPEG. Digital transmission, using adapted streaming techniques is another research area. Autostereoscopic, holographic and volumetric displays have been demonstrated and used. Signal processing techniques are employed to find the technology-dependent display driver signals to get the 3D images from abstract 3D scenes.