Tartu University researchers make imaging technology breakthrough
Researchers at the University of Tartu's Institute of Physics have developed a new imaging technology that allows the depth of field to be adjusted independently of lateral resolution.
Shivasubramanian Gopinath, one of the researchers working on the project, told ERR that currently it is not possible to alter the resolution of an image after it has been captured. "If we change the axial resolution, the lateral resolution changes as well," he explained.
Additionally, the accuracy of the colors can suffer. "This means that if you're filming with a camera and there are several people in the scene, the camera focuses on one person, while the others in the background become blurry. To make those in the background visible, the scene needs to be re-recorded," he added.
However, Gopinath's research team has developed a method that, in the future, could allow such scenes to be captured in a single shot. This means that the depth of field can be adjusted after the fact. "If we want to reduce the blur of the person standing in the foreground, we can do that. If we want to see the people standing more clearly in the background, we can do that too," Gopinath noted. The same method can also be applied in microscopy, for example.
To change axial resolution without affecting lateral resolution, Gopinath and his colleagues conducted experiments using Airy beams. These are a group of light waves that can move along a curved trajectory without any external influence. While conventional light beams tend to spread out as they travel, Airy beams maintain their shape over longer distances.
"We recorded Airy beams in groups of four to create distributions or ensembles. For a 3D object, multiple Airy distributions are needed. By adjusting the strength of these ensembles, we can control the post-capture depth of field," Gopinath added.
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Editor: Marcus Turovski