MSU Graphics & Media Lab Report #3 on stereo films quality assessment

Graphics & Media Lab CMC of Lomonosov Moscow State University has about 10 years’ experience in comprehensive analyzing of compressed video. In March 2013 Graphics & Media Lab (in cooperation with IITP RAS) has already released two reports on stereo films quality assessment since March 2013. In these reports we presented our evaluation results and overall quality comparison of 10 stereo films altogether.

After a very successful release of Avatar the interest to stereo 3D films endures now a bad slump. Some people even think that 3D is dying and has no future. This decline of 3D demand has a serious background: many movie goers experience headache and eyestrain while watching a stereo film.

The Lab decided to analyze the stereo films and to investigate the potential reasons of the irritating annoyance. The first two reports were focused on films captured with stereoscopic camera systems, and the main problems discovered during the film analysis were:

Image #1: Example of the sharpness mismatch

We’ve received a lot of positive comments from professional stereographers on these reports and were encouraged to continue the work on stereo film evaluation.

Andrew Enyart (Stereographer, VFX Supervisor)

In many cases flat scenes are simply victims of declining budgets. Often times, companies will prioritize shots on the basis of length or fast motion the idea being that if a shot is very short/fast, no one will notice that it is 2D. For the most part, this approach is acceptable to the viewing public because they simply don’t notice or don’t care. One of the problems of intercutting 2D and 3D is the cumulative result of the brain expecting something it doesn’t get. Over time, this mismatch in perception and expectation can result in a form of motion sickness (similar to when the ears and eyes don’t agree on what they are perceiving).

We are planning to publish three more reports in the 2nd half of 2013 and invite the stereographers for cooperation. Also, we are working hard to present our analysis of a stereo-window violation effect, which may be especially annoying in the more visible parts of the image. This issue appears in both captured and converted S3D films.

Now we would like to introduce our third report, in which we for the first time evaluate converted S3D films. The report includes the following converted S3D films:

2D-3D conversion introduces many new problems which are absent in captured S3D video. In our third report in addition to the problems, which were the focus of previous reports, we examine two common issues of converted S3D films:

Image #2: Example of the cardboard effect: objects appear to be flattened in depth

Image #3: Example of the edge sharpness mismatch

In the overall comparison of the examined films we compare 15 S3D movies altogether from all three reports.

Depth Budget

The report also provides the depth budget chart for both converted S3D films and captured ones (Image #4). It’s clear from this chart that ‘Green Lantern’ has no objects in front of the screen, while ‘Alice in Wonderland’ has.

Image #4: Depth Budget vs. Release Date

Vertical Disparity

It’s also noticeable that converted S3D films generally have better vertical alignment than captured S3D films (Image #5). In fact, ‘Abraham Lincoln: Vampire Hunter’ has the best vertical alignment among the processed films.

Image #5: Vertical Disparity vs. Release Date

Color mismatch

The same refers to color mismatch: the converted S3D films generally have much better color alignment between the left and right stereoscopic images (Image #6). However, color mismatch still appears in converted S3D films and it turned out that color mismatch in ‘Alice in Wonderland’ was stronger than in ‘Clash of the Titans’.

Image #6: Color Mismatch vs. Film Budget

Comparison of 2D & S3D versions

The report also contains a comparison of 2D & S3D versions of all five films. This research has several goals:

Acknowledgements

We would like to thank the following people for providing valuable comments, opinions and feedback, which helped us to improve this report:

A key motive of this report is to improve the stereo quality and therefore to reduce eye- and headache. The Graphics & Media Lab hopes, that a high 3D video quality would contribute to a continually increasing number of people, leaving the modern theaters without annoyance and with good impressions from the image quality and storytelling. The report is available to all who may be concerned and interested in improving the quality of stereoscopic content. The next reports on 3D quality will be published in the near future on the website.

Reports overview

Stereo-analysis project description

Report 1 (S3D shooting quality analysis of 5 movies) Download
(Additional info for bloggers and press)
Pages: 246
Figures: 295
Report 2 (S3D shooting quality analysis of 5 movies) Download
(Additional info for bloggers and press)
Pages: 342
Figures: 442
Report 3 (2D-3D conversion quality analysis of 5 movies) Download
(Additional info for bloggers and press)
Pages: 305
Figures: 336
Report 4 (S3D shooting quality analysis of 5 movies) Download Pages: 301
Figures: 402
Report 5 (2D-3D conversion quality analysis of 5 movies) Download
(Additional info for bloggers and press)
Pages: 384
Figures: 404
Report 6 (Stereo Window analysis of 10 movies) Download
(Additional info for bloggers and press)
Pages: 415
Figures: 455
Report 7 (Stereo Window analysis of 10 movies) Download
(Additional info for bloggers and press)
Pages: 333
Figures: 348
Report 8 (Rotate Analysis, Temporal Shift, Channels Swap, Zoom Mismatch in 25 movies) Download
(Additional info for bloggers and press)
Pages: 366
Figures: 361
Report 9 (Temporal Shift, Stuck-to-Background Objects, 2D to S3D conversion in Captured Films) Download
(Additional info for bloggers and press)
Pages: 467
Figures: 529
Report 10 (Overall analysis of 105 movies) Download Pages: 211
Figures: 270
Report 11 (Overall analysis of 10 selected Chinese movies) Download Pages: 322
Figures: 566
Report 12 (VR180 Quality Analysis) Download Pages: 348
Figures: 362

Contacts

For questions and proposition please contact us 3dmovietest@graphics.cs.msu.ru

14 Apr 2014
See Also
MSU Image- and video-quality metrics analysis
Description of a project in MSU Graphics and Media Laboratory
MSU 3D-video Quality Analysis. Report 12
MSU 3D-video Quality Analysis. Report 11
MSU 3D-video Quality Analysis. Report 10
Detection of stereo window violation
How to find objects that are present only in one view?
Depth continuity estimation in S3D video
How smooth is the depth transition between scenes?
Site structure