Meeting Stephen Hawking in person is already an exciting experience. But this time around, the hype was not about what the world-famous theoretical physicist said but the medium that he chose to deliver his lecture.
Hawking appeared as a hologram in front of hundreds of audience at the Hong Kong Science Park last month. With images being beamed live from Hawking's office in Cambridge, the technology involved goes beyond the speech synthesizer that the British scientist uses.
The holographic projection, which was slightly larger than the professor is in life-size, was created by ARHT Media. The Canadian startup has partnered with NetDragon Websoft, a Hong Kong-based online games company, to market the imaging technology in Asia.
Photo-realistic human holograms are not new.
Although they are still a novelty in commercial application, they have been used by the entertainment industry which deems the six-figure production cost affordable.
Digital Domain, the Hong Kong- based owner of the Playa Vista visual effects studio, has resurrected a number of deceased singers, such as Tupac Shakur and Teresa Teng, through its hologram project. The virtual image of Teng performed on stage with Taiwanese pop singer Jay Chou in 2013.
ARHT Media is prioritizing application in education over entertainment, though. It wants to bring its HumaGram technology to students and teachers, building a "low cost, high distribution" learning platform that will pull together "some of the best educators in the world."
"We believe the Asian market, in particularly China, represents a fertile ground for us to realize this technology," said Paul Duffy, president and chief executive of ARHT Media.
"In Hong Kong, we are actively pursuing a number of universities and corporations."
The demonstration event in Hong Kong showed a glimpse of what to come. During the 90-minute lecture, Hawking spoke and answered inquiries about his career, current research, and where he stands on the issue of Brexit and Donald Trump.
Despite the speaker's immobility and monotonous computer voice, the crowd was listening attentively. The novelty factor of hologram has prolonged the audience's attention span, with them marveling at the life-like eyes and lips movement captured and recreated on stage.
Hawking's lecture was taped. It will be broadcast as a pay-per-view program.
"We have an open system concept, which works on all devices - television, smartphone, iPad and augmented reality headset," said Simon Leung Lim- kin, vice chairman and executive director of NetDragon Websoft. "All the experiences that we capture will be able to enjoy on any devices, anytime anywhere."
Creating a human hologram is simpler than one would imagine. Hawking was seated in front of a green screen that measured four-meter wide and eight- meter tall. Multiple shots were captured in advance. However, a single-camera setup would suffice during a live broadcast.
Transmitting the hologram required technical specialty. The Toronto-based company has developed an exclusive video codec to package the audio and images that can be send with low latency over a cloud-based media server and broadband internet connection.
"We are able to create a primary, secondary and tertiary format so we have redundancy built in the system. When we have a clean line, which is typically what happens when we set up, we are able to take a human hologram from Los Angeles to Hong Kong in 400 to 700 milliseconds,' Duffy said.
In regions such as the mainland, where landline internet connection is unstable and expensive, sending a partial hologram - only the face, instead of the full body, as an example - is one solution.
Another option for transmission is via mobile phone network.
"We typically need anywhere from two to 10 megabytes per second for transmission. That's the low end of the 3G. So most of the transmissions that we are doing now can probably be provisioned through a cellphone network,' he added.
Reproducing a human hologram does not require the use of a special projector.
But special mesh-like screens are needed. Two screens were used at Hawking's lecture: a nine-meter-wide, four-meter-high one fixed at mid-stage, and another in the rear of the stage.
The virtual Hawking was projected in-between the screens. It was, in fact, a two-dimensional image. But stage lighting and fancy graphics could fool the human brain, making the screens invisible and the image convincingly three-dimensional, explained an engineer of ARHT Media.
The company is creating a smaller type of special screen for schools and home users. The new screen measures two-meters high and one- to - two- meters wide. Only one of them, rather than two, is required to render a hologram image.
While human hologram is not as widely popular as other existing types of video streaming technologies, important early adopters exist.
Duffy predicted that a critical mass of clientele will form when the price for purchasing projection equipment falls under a thousand US dollars.
"The cost to build a display station is coming down dramatically. And mass proliferation of virtual reality and augmented reality headsets all make for the ability to create a fully formed human experience but in a life-size model," he said.
"In the US, it costs from a few hundreds dollars all the way down to US$50 or US$60 a month to lease one of these projectors. It's getting quickly into the realm of what's possible for mass distribution."