Each of the processing steps described above may introduce artifacts into the 3D image or video data leading to a decreased quality of experience for the user. In the following the influence of each of the steps is summarized :
- Capture: Unnatural correspondences between the stereo pair should be avoided through careful camera positioning and rendering parameters.
- Representation: Each of the different formats (multiview, image+depth) and the conversion between them may introduce specific artifacts.
- Coding: 2D coding approaches are often adapted for 3D coding. This may lead to a loss of image details which are important for depth preception
- Transmission: The most common problem in digital transmission is packet loss. Error resilience and concealment techniques not specifically adapted to 3D data may introduce additional artifacts.
- Display: Each of the various display technologies may introduce different artifacts which very often also depending on the scene.
Apart from the typical 2D image and video artifacts such as ringing, blocking, freezing and jerkiness the quality of 3D data largely depends on artifacts that affect the 3D perception. Most of tthe following artifacts will cause an unnatural depth perception and leasd to nausea and cybersickness:
- Keystone distortion
- Puppet theater effect
- Cardboard effect
- Shear distortion
- Picket fence effect
For a reliable quality assessment both 2D and 3D artifacts and their interaction have to be considered.