Issue: Volume: 25 Issue: 1 (January 2002)

Depth Perception

An entertainment store uses 3D music videos and film trailers to attract customers

By Karen Moltenbrey

To draw the attention of holiday shoppers, retailer Wherehouse Music used Dynamic Digital Depth's (DDD) 3D television system to showcase a selection of music videos and movie trailers in three-dimensional format.

"Watching content in 3D is still a unique experience for the average consumer, so a person tends to watch promotional material much longer if it's in 3D because the look is so different," says Renee Geddis, vice president of marketing and advertising for Wherehouse Music. "Our hope is that if we can attract attention to these clips, the consumer will be more likely to purchase the music or DVD."

Wherehouse Music provided DDD (San ta Monica, CA) with several music videos from artists such as Madonna, Britney Spears, and Alicia Keys, along with film trailers from Dr. Seuss' How The Grinch Stole Christmas, Shrek, and Jurassic Park 3. DDD then used its TriDef technology to convert the 2D video content into imagery that could then be viewed in 3D without the need for special glasses to see the stereoscopic effects.
Warehouse Music teamed with Dynamic Digital Depth to provide holiday shoppers with a unique look at the latest movie trailers and music videos by presenting them in stereo.
Images courtesy Dynamic Digital Depth.

"Everything you see on the screen [in 3D] started out in 2D," says Chris Yewdall, DDD's president and CEO. "We use a sophisticated set of tools in the postproduction process that allows us to segment material filmed with one camera, and recover depth information to create both left- and right-eye views for depth."

Presenting the 2D images in 3D required a new content-creation process and a delivery mechanism. To create the stereo appearance, graphic artists at DDD digitized the original color material and converted it to grayscale, creating a depth map. To generate the depth maps they first selected the first and last "key" frame of each video, and assigned depth to objects in those frames based on their distance from the camera-those closer to the camera were lighter shades of gray, while those farther away were darker. To accomplish this, the artists used DDD's proprietary DepthMapper software to manually "airbrush" several spots of depth onto the images in those two frames, rather than precisely outlining each object. DepthMapper-which can distinguish among 256 shades of gray, far more than the human eye can perceive-searches for and automatically selects pixels in the images with shading similar to that of the pixels that were "depth sprayed" by the artists.

"It's a very fast process," says Yewdall. However, there is a creative aspect as well, even though the software automatically calculates a large percentage of the depth information for a scene based on the selective points chosen by the artists. "You lose all the original 3D depth information when ever the scene is transferred to a 2D format. Therefore, our artists must make certain determinations, aside from using the grayscale depth map," he adds.

Once the artists were satisfied with the 3D appearance of the two key frames, they used DDD's DepthTweener tool, which automatically assigns depth information to the imagery in the intermediate frames based on information "learned" from the depth information already assigned to the imagery by the DDD graphic artists. "During this process, we haven't changed the original 2D content," explains Yewdall. "Therefore, the segment can still be viewed in 2D format."
When Dynamic Digital Depth's TriDef 3D TV System is used with a 3D-capable screen, the filter on the screen tricks the eye into seeing in stereo, similar to the effect shown in this image, even though the segment is actually projected in 2D.

In most instances, the group converts 2D video originating from camera shoots. However, the process can also work with 2D imagery that was originally created with 3D software, as was the case with Shrek.

"If we can get the 3D data before it is discarded after the rendering process, it makes the conversion process much easier-about two-thirds faster," says Yewdall. In such instances, the group extracts the depth data directly from the 3D animation package, so there is no subjective input from a graphic artist.

When the depth process is completed, the group has two separate sets of data: the original 2D information and a corresponding depth map for each frame in the video, which is used to generate a left- and right-eye view for stereo.

Next, the team compresses the depth map and encodes it along with the unchanged 2D image into an mpeg video signal for a DVD, PC hard drive, or other delivery mechanism using a format that is compatible with current mpeg standards. A software decoder resident on a PC that drives the application translates the data based on the type of 3D screen that is being used to project the stereo imagery, and combines it with the original 2D content to produce a 3D image specific for that screen.

Once the team gets the video into its 3D format, it uses an off-the-shelf PC with a 1.5ghz processor and an Nvidia GeForce graphics card, which is plugged into any LCD or plasma screen with 3D capability. For the Wherehouse Music application, the group used a 50-inch Pioneer plasma screen modified by 4D-Vision. The 3D screens have a wavelength optical filter on their surface. When used in conjunction with DDD's TriDef playback software running on the PC, the screen fools the eye into seeing depth, even though the images are presented a flat screen. Because the system optimizes the content for a particular screen size and format-for instance, a computer monitor or projection or video screen-issues relating to stereoscopic viewing, such as eye strain, become irrelevant.

According to Yewdall, the biggest challenge so far has been convincing clients that the technology realy does allow people to see in 3D without using glasses. "There's been so many ho key attempts at 3D in the past that there is a general interest but at the same time reticence to believe this is true. Only when people see it can they appreciate what we are saying," he says. "We've cracked the fundamental requirements that make 3D viable to the mass market."

In fact, Yewdall points out that there is a growing interest within the consumer electronics industry to bring a 3D viewing experience to the home within the next few years.

"Think of it as a logical transition from black and white to color and now to 3D. In the 12 months since the 3D screens have come to market, we've been able to demonstrate the what we see as the future of television," Yewdall says. "So while the technology is now coming to a mall near you, by the middle of the decade, it'll probably be coming to a Circuit City or Best Buy near you."

Adds Geddis: "I think the consumer is ready for a new way to watch television. It's been a long time since there has been a new opportunity in that area." Until then, seeing in 3D will remain a unique viewing experience, making the medium an innovative advertising tool.

Key Tool: TriDef 3D TV System, Dynamic Digital Depth (