What’s on the Menu for 3D?

As TV takes its first steps towards 3D, practical problems are becoming more apparent. One deceptively complex issue is: what interface will be used by viewers to navigate the channels? Two factors deserve consideration.

First, just like most HDTVs, it seems likely that most 3D TVs will utilize a set top box. The user interface or on-screen menu that is used to navigate the channels is generated in conjunction with the set top box.

Second, it seems all but certain that the first home 3D TVs will require viewers to wear some form of glasses. When operating the on-screen controls, viewers will not want to take off their glasses or to switch back into the normal 2D mode. A simple solution would be to overlay a 2D menu on top of the 3D image. Not all in the industry agree that this is a good idea or, for that matter, that the approach is even workable.

One solution to the problem is being worked as a collaboration between Nagravision and 3ality Digital. In a blog entry published on Wired.com on October 6, 2009, Eliot Van Buskirk quotes Frank Dreyer of Nagravision as stating, "Once you have a TV that has a 3D mode, you need to stay in that mode in order to change channels, buy video-on-demand, see what’s on next, and that sort of thing."

A problem associated with a 3D menu is that it must effectively integrate into the 3D image. If it does not, the outcome can be visual distress. A challenge in creating an appropriate 3D menu derives from the fact that the design criteria are different from those of a 2D menu. The result is that just about every aspect of the menu design needs to be rethought and reconfigured.

Commenting on the Nagravision/3ality Digital approach, Dreyer stated that "Our 2D guide uses transparencies and drop shadows, and we’re making things bigger and using picture-in-picture - it’s kind of like this modern heads-up display. But in 3D, suddenly the video’s not a piece of glass behind the guide - it’s all immersive, so you can’t do transparency, you can’t bleed your graphics to the edges, you have to manage picture-in-picture very carefully, you have to set different font sizes and colors to manage the ghosting effect. There’s a lot of challenges."

Another factor related to the production of a 3D menu is that as much as twice the amount of calculation is required to create a 3D menu as is required to create a 2D menu. This is because two views are needed for the 3D case. 3ality Digital’s approach to this problem is to utilize metadata. In the next generation system, they propose that metadata streamed along with the video contain spatial information related to every frame. This information would be used by the set top box in creating 3D menus that effectively integrate with the 3D imagery. The advantage of this approach is that it moves some of the computational burden associated with creation of the menu to the production side, minimizing the extent of the computation required at the set top box. This reduces the complexity and the expense of the 3D enabled set top box.

In the blog, Van Buskirk describes his impressions of the 3D menus created and demonstrated by Nagravision/3ality Digital during a visit to their office. He states that the "elements popped out of the screen when selected, and selecting a movie from pay-per-view section felt a bit like picking out a movie off of the shelf at a brick-and-mortar rental shop (a comparison that could become more apt if remote controls evolve to take the Z axis into account). And I didn’t feel eyestrain toggling through the menu screens."

Dreyer predicts that 3D set top boxes using this menu system will enter certain markets by the second half of 2010 to target the first round of early adopters. Our bet is that Europe is a good place to look for these first rollouts.

By Art Berman, Display Daily