Software turns smartphone into 3-D scanner


Forensic investigators documenting tire treads or footprints, or plastic surgeons giving their patients a preview of proposed nips and tucks could soon have a new tool that simplifies their work.

Brown University researchers have developed a new 3-D scanning technology that could turn a regular digital SLR camera, or most smartphones, into high-quality 3-D scanners.

Industrial scanners use two primary parts: A projector that shines patterns of light on the object, and a camera that takes photographs of the object thusly lit.

Unlike a photograph in which a coffee cup is captured flat, the light patterning offers information about surface shape of the object — if it’s ridged, for example, or flat, or how steeply curved.

But scanners that work like this are typically expensive, starting at a few thousand dollars, which is part of the reason the Brown team came up with a workaround.

A team led by Brown professor Gabriel Taubin developed software that could sync up a basic light-pattern projector with a smartphone or camera that can work on “burst” mode.

The patterns illuminate an object in the right sequence as the camera takes photographs, creating a series of images that can then be stitched together to create a 3-D rendering, to use as a model on the computer or to run through a 3-D printer.

You could pick up any object — the curved receiver of a rotary phone, say — scan its surface, upload that scan to a computer program, and print out a replica.

“You need to capture an image at the proper time. You need the camera and the projector to be synchronized,” Taubin said.

The team presented its research at the Association of Computing Machinery’s SIGGRAPH Asia conference in November. Members explained how their algorithms would work and demonstrated the results using a store-bought digital SLR camera and a desktop projector used in staff meetings for PowerPoint presentations.

Those desktop projectors don’t come cheap either, but a projector created specially for scanning could be smaller and less expensive, Taubin said.

Nidhi Subbaraman writes about science and research. Email her at [email protected]
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