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Understanding Requirements for High-Quality 3D Video: A Test in Stereo Perception

[Philip Lelyveld comment: this article contains many useful graphs]

[3D Roundaout]

Initial questions

My company’s main interests are stereo correction, stereo conversion to multiview and 2D-to-stereo 3D conversion using depth maps. From a practical perspective, the following initial questions arise when developing algorithms and software for 3D video conversion and quality improvement:

• How significant is the difference in stereo perception among different people? What does the stereo perception ‘distribution’ function look like?
• Which characteristics of a stereo image are important for subjective perceived quality?
• In which cases are stereo artefacts (due to imperfect 2D-to-3D conversion, stereo mismatch or a distorted depth or disparity map) noticeable, and when are they not so noticeable? When are perfectly-detailed depth maps important, and when are they superfluous?

A number of tests were conducted to find partial answers to these questions, and the work is still ongoing. The following issues were studied first:

• Stereo sensitivity, ability to perceive 3D.
• Subjective stereo acuteness.

Conclusion

On the basis of these stereo sensitivity and acuteness tests, several conclusions can be drawn and common-knowledge opinions confirmed:

• Variance in subjective stereo perception is very large. Up to 30% of test participants are barely susceptible to stereo for, apparently, various reasons – even in the case of close-to-normal 2D vision. Weak 2D vision is not the only cause of bad stereo vision, although it does have an influence. Thus, the question arises, to what extent is it conditioned by the particulars of artificial digital stereo, and to what degree is it due to the individual properties of eyes and the brain’s sensory system?

The second question relates to whether there is a strong relationship between stereo sensitivity and comfort when viewing the same stereo video. If such a relationship exists, how should 3D video be prepared for people with different stereo perception characteristics?

• Subjective stereo perception is adaptive. This conclusion does not relate only to the latency of proper eye convergence; some brain learning is involved. After training, people notice more 3D details under the same conditions. This result is related to the assertion that drastic depth changes over time should be avoided in stereo video, as they ‘defocus’ stereo vision.

• For depth map construction and stereo generation, an important conclusion is that roughness and deviations in depth that are irrelevant to the underlying 2D image are noticeable as unpleasant artefacts only in highly-detailed areas with sharp edges. So, the masking effect of rough surfaces in 2D images, when artefacts in detailed areas are often imperceptible, works in the opposite way with stereo. Likely, very irregular textures are still less revealing because the brain must match numerous random-looking features that are hard to discern.

• 2D-to-3D conversion and stereo correction artefacts in flat uniform areas are invisible to nearly all viewers; only the borders of such areas should be accurately processed.

If you have a 3D display or a pair of red/cyan glasses (red for left eye, cyan for right) you can check your stereo vision using the methods described in this article by watching the following video:  …

Read the full article here: http://3droundabout.com/2011/12/5788/understanding-requirements-for-high-quality-3d-video-a-test-in-stereo-perception.html

Applied Optics Focus Issue: Digital Holography and 3-D Imaging

[Press Release]

Research into digital holography (DH), the process of electronically recording and numerically reconstructing an optical field, has made tremendous strides in recent years. To highlight breakthroughs in this area, the editors of the Optical Society’s (OSA) journal Applied Opticshave teamed with the editors of the journal Chinese Optics Letters to publish a special Focus Issue on Digital Holography and 3-D Imaging.  …

Key Findings and Select Papers

The following papers are some of the highlights of the Applied Optics and Chinese Optics Letters Focus Issue on Digital Holography and 3-D Imaging. See Volume 50, Issue 34 for the Applied Optics papers, accessible online at http://www.opticsinfobase.org/ao/issue.cfm. The Chinese Optics Letters papers will be accessible online at http://www.opticsinfobase.org/col/home.cfm.

  • In this paper, the authors discuss a novel technique called digitized holography. The wave field of real objects is captured in a wide area by synthetic digital holography, which is then incorporated in virtual 3-D scenes. The end result of the reconstructed 3-D images can be digitally editable, achievable and transmittable.

    Paper: “Digitized holography: modern holography for 3D imaging of virtual and real objects,” Applied Optics, Vol. 50, Issue 34, pp. H278-H284 (2011).

  • Compressing sensing is a technique to recover a sparse signal in the most efficient possible way. The technique has been used widely in signal and image processing as well as in computational mathematics. Compressive sensing applied to the reconstruction of holograms is a recent novel trend in digital holography and is called compressive holography. This article is a tutorial for general readers to understand compressive holography.

    Paper: “Sampling and processing for compressive holography,” Applied Optics, Vol. 50, Issue 34, pp. H75-H86 (2011).

  • Platforms of tomographic imaging using digital holography typically have relatively complex optical and mechanical setups. The present authors have recently developed lens-free optical tomography based on on-axis digital holography, which has relatively simple on-chip architectures and can be particularly useful for lab-on-a-chip applications with submicron-resolution. The article reviews this recently developed technique.

    Paper: “Partially coherent lensfree tomographic microscopy,” Applied Optics, Vol. 50, Issue 34 pp. H253-H264 (2011)

  • Conventional multiplex holograms are composed of a series of long thin individual holograms, which inevitably cause the reconstructed images overlaid with a picket-fence structure. The authors discuss a disk-type multiple hologram which is free from the picket-fence effect. In addition, the disk-type multiplex hologram has the advantage of commercial mass production owing to the utilization of the well-developed CD technology.

    Paper: “Image design for normal viewing image-plane disk-type multiplex hologram,” Chinese Optics Letters, Vol. 9, Issue 12, pp. 120003 (2011).

Read the full press release here: http://www.businesswire.com/news/home/20111207006220/en/Applied-Optics-Focus-Issue-Digital-Holography-3-D

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Studio Technology Leaders Dinner 2017

The Entertainment Technology Center at the University of Southern California held its 2017 Studio Technology Leaders Dinner at NeueHouse in Hollywood. Sponsored by Western Digital, HGST and Equinix, the event honored former Sony Pictures CTO Spencer Stephens with the Bob Lambert Technology Leadership Award. The evening featured a panel of studio execs discussing new directions in film production, and a screening of “Wonder Buffalo,” the third R&D short produced under the auspices of ETC@USC’s Project Cloud to explore and test next-generation production processes. 

“Wonder Buffalo,” a coming-of-age story, was made possible through ETC’s 2016 Technology Award to filmmaker Christine Berg, who wrote the script with Simon Shterenberg.

The duo developed the project at the Writers Guild Foundation’s Veterans Writing Project, with the support of Disney/ABC Television Group, Warner Bros., NAGRA Kudelski Group, Technicolor, 8i, Realtra, Equinix, Sony Electronics, Amazon Web Services, the Creative Visions Foundation, The World Building Institute and the USC School of Cinematic Arts. It was also executive produced by Erik Weaver, HGST global director of M&E strategy and market development and former head of ETC’s Project Cloud.

ETC executive director Ken Williams noted that the short tested not only cloud production and post production technologies, but was also processed entirely in HDR, and tested volumetric capture, photogrammetry, ambianic sound and interactivity, via a room-scale virtual reality component. “Wonder Buffalo” was shown at Sundance and invited to SXSW.

Williams (below left) presented the Bob Lambert Technology Leadership award to Spencer Stephens (below right), whose early career involved data communications and photography.
ETC_Williams_Stephens_AwardStephens joined Disney TV Animation in 1997, as the company transitioned from traditional to digital production. He later joined Chris Cookson’s Technology Operations at Warner Bros., ultimately building the 4K production capability for Warner’s Motion Picture Imaging post house, which he then ran. He followed Cookson to Sony Pictures where he became CTO. He’s left Sony, but is not retired.

Walden Pond chief executive Wendy Aylsworth, a previous Bob Lambert Technology Leadership awardee; Sony Pictures Home Entertainment senior vice president Richard Berger; and former Sony Pictures Technology president Chris Cookson all spoke about Stephens’ achievements.

“If I’m in a crisis, I want Spencer by my side,” said Berger. “The scope of his knowledge knows no bounds.”

Stephens thanked Williams, the ETC board and Dean Elizabeth Daley of the USC School of Cinematic Arts for the award, and Cookson for hiring him twice. He also recalled his close connection with Lambert, who recommended him for the Disney job and then introduced him to Cookson.

Last, ETC hosted a panel of studio executives, including 20th Century Fox CTO Hanno Basse, Sony Pictures Entertainment CTO Don Eklund, Paramount Pictures EVP Anthony Guarino, Warner Bros. Technology EVP Justin Herz, Walt Disney Studios CTO Jamie Voris and Universal Pictures CTO Michael Wise. Moderated by Williams, the panel addressed pain points in the production process, significant opportunities opened up by technology, and how studios are handling change.

Panelists described the challenges of handling thousands of VFX shots from multiple cameras with differing resolutions, color spaces and formats, and putting it all together under increasingly tight deadlines. They noted that “Wonder Buffalo” has helped to shine a light on the issues, which also include the sheer size of files and massive number of deliverables. They also identified security as a “huge issue.”

New technologies have produced automated workflows and enhanced global creative collaboration, as well as significantly accelerated real-time rendering. Panelists noted that physical media isn’t going away any time soon, and that consumers are the big winners in an era in which there are so many platforms and distribution is not getting in the way of finding and enjoying content.

They also underlined that the studios have gone through many technology changes over the decades and that their resilience in managing change bodes well for the future, even as viewers redefine entertainment.

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