**6.3 Classic video methods of quality assessment**

Further analysis suggested that visible 2D artifacts detract from stereo quality even more than they do in the conventional 2D (non-stereo) image.

As any type of video, sterescopic video is acceptable to be evaluated by classic methods of quality assessment, including subjective and objective (FR or NR).

These video sequences admit metrics such as PSNR or blocking and blurring measurement, because they have also be processed using same techniques as 2-D video (i.e. H.264, MPEG-2; VC-1).

But stereoscopic video has the advantage of disposing two views (left and right) wellcorrelated. This fact could benefit the assessment, since for normal (without excesive parallax) 3-D captures, one view could be used to predict the second one.

### **6.4 Visual comfort and fatigue**

The visual comfort of stereoscopic images is certainly one of the most critical problems in stereoscopic research. The term visual discomfort is generally used to refer to the subjective

 Frame Compatible Service (FSC). In FSC, both views are content in the same frame. The disadvantage of this system is the reduction of resolution of the complete image (this

 Service compatible (SC). MVC (Multiview Video Coding) is the main standard for this type of services. This standard is an amendment to H.264/MPEG-4 AVC video compression standard that enables efficient encoding of sequences captured simultaneously from multiple cameras using a single video stream. MVC is the standard used in Blu-ray 3D releases, because allows older devices and software to decode stereoscopic video streams, ignoring additional information for the second

Also, depending on the type of 3D display, the method of assessment is different, according to the settings of each technique used. The groups of technologies according to its

 Passive glasses (normally with circular or linear polarization). In FSC, both views are content in every frame. The glasses help the eyes to separate the views and

 Active glasses. The image is presented to each eye alternating from one view to other every frame. The system must assure the synchronism between display and glasses.

 Without glasses: Autostereoscopic. Different techniques, such as parallax barriers or lenticular displays, are used for this purpose, but there is still a lot of work in this field.

Further analysis suggested that visible 2D artifacts detract from stereo quality even more

As any type of video, sterescopic video is acceptable to be evaluated by classic methods of

These video sequences admit metrics such as PSNR or blocking and blurring measurement, because they have also be processed using same techniques as 2-D video (i.e. H.264, MPEG-

But stereoscopic video has the advantage of disposing two views (left and right) wellcorrelated. This fact could benefit the assessment, since for normal (without excesive

The visual comfort of stereoscopic images is certainly one of the most critical problems in stereoscopic research. The term visual discomfort is generally used to refer to the subjective

There are different versions of these services: side-by-side, up-down, line-by-line and

fact affects to the global quality) but the synchronism is assured.

redirect them to the corresponding eye.

Serious quality studies are developed.

**6.3 Classic video methods of quality assessment** 

than they do in the conventional 2D (non-stereo) image.

quality assessment, including subjective and objective (FR or NR).

parallax) 3-D captures, one view could be used to predict the second one.

view.

With glasses:

2; VC-1).

**6.4 Visual comfort and fatigue** 

displaying technique are:

checkboard, depending on the way of distributing both views in the frame.

sensation of discomfort often associated with the viewing of stereoscopic images. Sources of visual discomfort may include excessive binocular disparities, conflicts between accommodation and vergence (the simultaneous movement of both eyes in opposite directions), appearance of specific artifacts such as crosstalk or boundaries and imperfections in 3D rendering.

A large number of studies have been developed in order to predict the response of the user to this parameter, analyzing the maximum exposure time to avoid the fatigue and the main reasons of visual discomfort, in order to avoid it in the future and obtain better quality of experience. M. Lambooij reviews the principle conclusions in this field.
