Digital

Nova tecnologia de smartphone 3D poderia mudar a fotografia, dizem especialistas

Your next smartphone could have a camera that sees in three dimensions, opening up a new range of possibilities for apps ranging from fitness to photography.

Conteúdo

  • Getting a different view
  • The 3D revolution

Researchers at Stanford University have created a novel approach that allows standard image sensors to see light in 3D. The technique would allow cameras to measure the distance to objects and make three-dimensional imaging widely available in smartphones.

“Existing 3D cameras need specialized pixels, which are difficult to realize in large formats and have smaller fill factors due to the complex electronics required to capture 3D in the pixels,” Okan Atalar, a doctoral candidate in electrical engineering at Stanford University and the first author on a new paper that describes the new system, told Digital Trends in an interview. “Our approach converts standard and highly advanced 2D sensors into 3D sensors as opposed to building them from the ground up.”

Getting a different view

Measuring distance between objects with light is currently possible only with specialized and expensive lidar — short for “light detection and ranging” – systems. Lidar uses a laser that shoots at objects and measures the light that bounces back. It can tell how far away the thing is, how fast it’s traveling, whether it’s moving closer or farther away and whether the paths of two moving objects will intersect.

The Stanford researchers’ new approach could enable megapixel-resolution lidar – a level that’s not possible today. Higher resolution would allow lidar to identify targets at a greater range.

One way to add 3D imaging to standard sensors is by adding a light source and a modulator that turns the light on and off millions of times every second. By measuring the variations in the light, engineers can calculate distance. Existing modulators require impractically large amounts of power.

The Stanford team solved the modulator problem by using a phenomenon known as acoustic resonance. The researchers built an acoustic modulator using a wafer of lithium niobate – a transparent crystal that is highly desirable for its electrical, auditory, and optical properties – coated with two transparent electrodes.

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The new modulator’s design is simple and integrates into a proposed system that uses off-the-shelf cameras, like those in everyday cell phones and digital SLRs. Atalar and his advisor Amin Arbabian, an associate professor of electrical engineering and the project’s senior author, said it could become the basis for a new type of compact, low-cost, energy-efficient lidar, “standard CMOS lidar” as they call it, that could find its way into drones, extraterrestrial rovers, and other applications.

“Our approach could also work in the infrared regime,” Atalar said. “No IR image sensor can detect depth without requiring significant modifications.”

Apple includes lidar on its current iPhone 13 Pro and iPhone 13 Pro Max models. The company says the system offers better low-light focus and improves night portrait mode effects. The Stanford researchers said their lidar solution is less expensive to implement than the one used by Apple and could be installed on a wider range of phones.

Lidar scanning devices are used to determine the depth of a photo, Hans Hansen, the CEO of Brand 3D, a 3D photography company, told Digital Trends. By moving the camera around the object, the distances from multiple angles can be used to create a full 3D model. There’s also stereo photography where multiple cameras are placed apart (for example the three-camera lens module on Apple iPhone Pro phones) and then use the information to create a spatial image of a scene or an object.

“We’ve seen use cases from measuring the wall distance in your home and other spatial measurements,” Sukemasa Kabayama, the CEO of Uplift Labs, which uses 3D analysis to analyze human performance using smartphones, said to Digital Trends. “Although those are not 3D cameras specifically, these smartphone cameras have the power to capture valuable data and produce 3D visualizations using video and other applications.”

Recently, researchers from MIT developed ultra low power radars that use regular radar technology to detect distances to moving objects. This technology could eventually be suitable to make a new type of camera that would not be sensitive to light issues, e.g. when scanning transparent objects.

The 3D revolution

Widespread use of 3D technology could dramatically change photography, experts say.

“With 3D cameras, you would be able to capture scenes and objects that people remotely would be able to experience as if they were physically in the room,” Hansen said. “This would be groundbreaking for remote working, learning and for safe distances during pandemics, as well as for diagnosing, treating and repairing functions in healthcare, technology, and manufacturing sectors.”

Kabayama disse que a imagem 3D coletada por smartphones poderia fornecer analíticas e aprimoramentos detalhados em várias indústrias. Uma área onde a tecnologia 3D pode ter um impacto é esportes, fitness e bem-estar.

“Se você é um junkie crossfit, golfista de fim de semana ou entusiasta de Avid Peloton, o risco de lesão física está presente e para muitas, uma batalha constante”, acrescentou Kabayama. “Os atletas profissionais têm acesso à tecnologia 3D que serve como uma maneira de minimizar as lesões relacionadas ao desempenho, mas a maioria dos atletas todos os dias não.”

Kabayama previu que, fazendo câmeras 3D e análise acessível através de smartphones, os atletas de todos os conjuntos de habilidades podem rastrear e analisar seu movimento para obter análises biomecânicas detalhadas.

“Com a maioria dos ferimentos devido a superexerção, forma inadequada, ou outras mecânicas deficiente do corpo, a imagem 3D pode tornar as áreas de melhoria – se essa seja formada ou partes do corpo para fortalecer – uma tarefa perfeita”, acrescentou.

Ter uma câmera 3D no seu dispositivo móvel também pode torná-lo mais seguro. Afinal, a segurança baseada na face em telefones é tão boa quanto a câmera por trás disso, Richard Carriere, vice-presidente sênior e gerente geral do CyberLink, que torna a tecnologia de reconhecimento facial, disse em uma entrevista.

ID de rosto, por exemplo, que muitas pessoas usam para obter acesso a contas sensíveis, como contas bancárias móveis, trabalhar e-mails e pagar via smartphone, são executadas no sistema de câmeras de TraveRePth da Apple. As câmeras 3D mais avançadas chegando ao mercado são capazes de capturar leituras ainda mais detalhadas de profundidade, disse Carriere.

“A precisão aprimorada não apenas reduz o número de vezes que a tecnologia não consegue digitalizar seu rosto corretamente, talvez porque você está em um ângulo incomum, mas também salvaguardas criticamente contra tentativas de falsificação”, acrescentou Carriere.