3D Challenges Not Insignificant

We reported last month that the Blu-ray Disc Association announced its plans for incorporating 3D into the Blu-ray Disc format. Based on some interesting comments we received from readers, we thought some further discussion was in order.

"Does anything in the BDA news suggest that their pending standard is somehow linked to a specific display technology? Won’t these new 3D BD movies also play on 3D displays that use passive 3D glasses? JVC, Hyundai and LGE have products with passive glasses that certainly expect to support the BD standard. The requirement for 1080p to each eye is only a requirement for the content on the disc and the content on the interface; it has no bearing on what happens downstream of the interface."

Yes, it should be stressed that the BDA did not explicitly endorse any particular display technology in their press statement. Nonetheless, there is a plausible argument that their requirement of "full 1080p resolution to each eye" in fact sets the stage for the active-shutter approach. Only frame interleaving, which is used by Panasonic, for example, provides full 1080p resolution. Polarization, as predominantly used in the passive approach, does not allow full 1080p resolution at the display, as the image is decimated (line interleaved) to provide the 3D isolation between left and right eye images. (Some polarized displays have in fact been developed, for gaming and professional applications, that provide full resolution. The display technology, however, comes at a severe cost premium, and some models suffer from relatively high amounts of crosstalk, or ghosting.) 1080p content from a disc could play on a passive system, but would require a signal processor in the TV to down-sample the image, adding some complexity and cost.

In principle, then, the BDA requirement of 1080p 3D on the BD could be viewed as an implicit endorsement of the shutter-based spec. Sony and Panasonic, which have shown active-shutter 3D displays, serve on the board of directors of the BDA, and both companies have indicated that they plan to have 3D products in the marketplace soon. LG, which has shown prototype passive-glasses 3DTVs, also serves on the BDA board, but has not made an explicit announcement regarding product availability.

"I expect 3DTV to have hardware/software to transcode and/or scale 3D signals in many formats to the native 3D display format of that particular TV."

Yes, absolutely, but that doesn’t come for free. Supporting multiple formats in a small handheld device may be a challenge when the profit margin is very small. If the development cost and IC roadmap for large displays can trickle down to small displays, this will eventually become a non-issue. But the maturity process will take time.

"The spec for 3D content distribution on mass media has to be 2D compatible or the growth of the 3D ecosystem will be crippled."

This is very important, as the public will not want to have multiple disc players for a single TV, nor will they enthusiastically buy multiple versions of the same content. The BDA realizes the importance of this, and so the specification will require backward compatibility for both discs and players. It is unclear, however, whether all new Blu-ray disc players will be required to support 3D playback of 3D discs.

"[We need to] decouple content creation from display and application."

All content must be produced in a way that supports different display technologies. This is easier said than done, however, as content distributors now know; supporting multiple displays and media - full-size TVs, handhelds, the Internet - is an expensive and challenging proposition, from a production standpoint. For this reason, there will always be some correlation between the content creation process and the display of said content on different devices.

What we take away from this discussion is that any new technology/content proposition carries with it the challenge of manifold device support and compatible production techniques. Can the industries involved rise to the challenge?

By Aldo Cugnini, Display Daily