Telemedicine, microscopy and other fields work with high-definition images on ultra-fast optical networks. Advances in these areas could also help improve academic Internet performance (image: Agência FAPESP)

October 08, 2014

By Elton Alisson

Agência FAPESP – In late August, a group of Brazilian researchers transmitted a live version of a 15-minute-long 1929 São Paulo silent film, São Paulo, a Metropolitan Symphony, in 4K resolution (with image definition four times better than full HD television) from the main theater of the School of Medicine at the University of São Paulo (FMUSP) in downtown São Paulo to the New World Symphony concert hall in Miami.

Simultaneously, another group of researchers transmitted the same film, projected in the concert hall of the American orchestra, from Miami to São Paulo in real time – but its sound track was being played live by a trio of instrumentalists in surround sound (on 24 audio channels).

The demonstration, made using a 10,000-km grid of underwater fiber optic cables between São Paulo and Miami and a connection speed of 10 gigabits per second (Gbps) is one of the high-definition image transmission technologies on ultra-fast networks that are the subject of research in the fields of cinema and digital media.

In addition to its use in the entertainment industry, the technology has been applied to various fields of science and in scientific communication and may help solve problems found with the academic and commercial Internet, say researchers who took part in CineGrid Brasil, an international conference held August 28–29, 2014 at the FMUSP theater.

“We believe that high-definition images will replace the 35 mm film used in movies up to now due to its quality and the potential for online real-time transmission,” noted Jane de Almeida, professor and researcher at the Laboratory of Cinematic Arts and Visualization (LabCine) of the Mackenzie Presbyterian University and one of the event coordinators, in comments to Agência FAPESP.

“The purpose of high-definition images is to enable an “expanded” cinema, one that extrapolates the traditional space of conventional movie theaters and allows images in high-resolution to be displayed in real-time in multipurpose spaces, with applications in fields like telemedicine, astronomy and microscopy,” said the researcher.

Laurin Herr, founder of CineGrid, said in a lecture at the event that the entertainment, art and culture, and science and technology sectors are driving digital media and that they all share the same needs. “The three fields need more speed and easier access to the Internet, in addition to better computers and equipment to store, distribute and visualize ever-larger amounts of data,” he said.

Evolution of the technology

According to the expert, initial attempts at digital cinema were made by the Japan Broadcasting Corporation (NHK) in the early 1980s.

In a 1981 conference on television and cinema engineering held in Los Angeles, researchers from the Japanese public radio broadcaster demonstrated an HDTV projector that piqued the interest of filmmakers such as Francis Ford Coppola, director of the Godfather trilogy and many other films. The technology, however, took more than 20 years to be developed by Nippon Telegraph and Telephone, a Japanese telecommunications company, which presented the first 4K digital cinema system to the world in 2001.

Since the early 2000s, however, major studios have begun to test a technology used to capture digital images called 2K, with a resolution of 2,048 x 1,080 pixels, slightly superior to HDTV, which provides images at a definition of 1,920 x 1,080 pixels.

Starting in 2006, studios began using 4K technology, which doubles the horizontal dimension to 4,096 x 2,160 pixels, becoming the second digital image format currently adopted by the industry, along with 2K.

“Today, 4K is not just a theory but one already found in movies, television, videogames, science and medicine,” said Herr.

“The best 4K resolution technology enables larger images with more detail and more immersion. At the movies, this allows the public to become more involved in the film. In the sciences, it allows researchers to better visualize a microorganism or a human organ, for example, at higher definition,” he said.

On August 29, 2014, the event’s final day, there was a live transmission of a cataract surgery conducted at the Opthamology Department of the Federal University of São Paulo (Unifesp) to the FMUSP theater using two 4K cameras attached to a microscope on the 10 Gbps ANSP (Academic Network at São Paulo, a FAPESP program) network.

In addition to showing the procedure in ultra-high resolution, the transmission technology allows more doctors in training to observe the details of the surgery, said Cícero Inácio da Silva, deputy coordinator of the Open University of Brazil (USB) at Unifesp.

“Generally, surgery such as this is observed by, at most, one student or medical resident, through what is known as ‘piggybacking’,” said Silva. “The 4K transmission of the procedure on a high-speed network allows an audience full of doctors in training to watch from an auditorium.”

In December, the researchers plan to transmit another ophthalmological surgery from São Paulo to Miami in 4K resolution, but this time in 3D.

Technological challenges

The goal of the experiments, in addition to demonstrating the viability of transmissions of large volumes of high-definition images to the research community, is to test the efficiency of the optical networks.

In countries such as the United States and Germany, these networks are already at 160 Gbps, equivalent to 160,000 times the average speed of broadband Internet in Brazil, at 2 Gbps. However, it is still difficult to transmit films in real-time due to problems such as delay (signal delay).

“Today, there is a 130-millisecond delay in data transmission via the fiber optic network between São Paulo and Miami, and a half-second delay between São Paulo and Japan,” said Luis Fernandez Lopez, general coordinator of ANSP. “In these two cases, there are physical problems that involve the speed of light in fiber optic cables, which is less than that in the vacuum and cannot be increased.”

The more serious problem in transmitting a 4K film over a high-speed network such as the one that connects São Paulo to Miami is that the film needs to be compressed into data packets of approximately 500 megabits per second – because a single image can have 8 megapixels (millions of pixels) – and decompressed upon arrival at the location where it is to be shown.

According to Lopez, the process of compression and decompression increases the delay and complicates the transmission problem. “If these 4K films could be transmitted without first having to be compressed, there would be less of a delay problem. So digital media professionals would like to have a 10 gigabit-per-second fiber optic network to transmit films in this image format without any transmission problems.”

According to Lopez, this same demand for faster and more efficient networks is shared by researchers in the fields of astronomy and particle physics.

By studying the problems related to quality control of the digital film transmission signal, solutions can be developed to improve the performance of academic networks.

“Assistance in conducting these demonstrations gives us at ANSP a huge advantage because they put us through the paces and prepare us to handle the demands of researchers from the state of São Paulo,” he said.

“When a particle physicist comes to us asking for a 10 gigabit per second link such as for CERN [European Organization for Nuclear Research, in Switzerland, which houses the Large Hadron Collider (LHC)], to perform experiments without any transmission failure or loss of data, we feel confident because we’ve already done it for the CineGrid,” he said.

Research community

This was the second time that the event was held in Brazil. The first was in 2011 in Rio de Janeiro. The event is organized in several countries by the non-profit international association CineGrid.

Established in the United States in 2004, the association was designed to constitute an interdisciplinary community focused on the investigation, development and demonstration of collaborative network tools that enable the production, use, preservation and exchange of ultra-high-quality digital media on high-speed fiber optic networks.

The association was conceived in the early 2000s, when the convergence of digital technology in the film industry began. Today, it boasts 50 members from around the world, including universities, research institutions, film studios, hardware and software developers and academic networks such as the ANSP.