Holography : Change sharpness of any object in an image once it has been captured
Quote:
Originally Posted by Charles Q. Choi, IEEE Spectrum, 12 Oct 2023
Impossible Photo Feat Now Possible Via Holography Now you can focus on anything while giving up nothing, with simple, cheap optics
Smartphones and movie cameras might one day do what regular cameras now cannot—change the sharpness of any given object once it has been captured, without sacrificing picture quality. Scientists developed the trick from an exotic form of holography and from techniques developed for X-ray cameras used in outer space.
They detailed their findings online on 20 September in the journal Optics and Lasers in Engineering.
A critical aspect of any camera is its depth of field, the distance over which it can produce sharp images. Although modern cameras can adjust their depth of field before capturing a photo, they cannot tune the depth of field afterwards.
True, there are computational methods that can, to some extent, refocus slightly blurred features digitally. But it comes at a cost: “Previously sharp features become blurred,” says study senior author Vijayakumar Anand, an optical engineer at the University of Tartu in Estonia.
The new method requires no newly developed hardware, only conventional optics, “and therefore can be easily implemented in existing imaging technologies,” Anand says.
It’s based in part on what’s known as incoherent holography. Standard holography generates holograms by illuminating objects with lasers, whose light is coherent, meaning all its light waves overlap essentially perfectly. When laser beams are made to interfere with one another in precise ways, the interference pattern encodes a three-dimensional representation of an object—a hologram.
Incoherent holography relies on normal light. One way it can work is by splitting light from a scene into two parts, making them interfere, and generating a hologram, all with the aid of computer processing. Incoherent holography may prove useful when, say, it may prove dangerous to light up living tissue with lasers.
The new study combines recent advances in incoherent holography with a lensless approach to photography known as coded aperture imaging.
Is that anything like the original Lytro was capable of doing?
Pardon my ignorance in asking, I haven't read the article and I really have to get to the shops so can't read it at the moment.
I have an original Lytro, it was amazing being able to alter the focus on the pc after taking the image.
