Refocusable Plenoptic Light-Field Photography

virgil_disgr4ce writes "Wired is reporting that a Stanford student using about 90,000 microlenses has developed a plenoptic camera whose images can be refocused, via software, after they are exposed." From the article: "'We just think it'll lead to better cameras that make it easier to take pictures that are in focus and look good,' said Ng's adviser, Stanford computer science professor Pat Hanrahan."

Comments

oh so 1996

[griffster]

http://graphics.stanford.edu/projects/lightfield/ If you've attended siggraph for the last 8 or 9 years you yawn with me.

Can't get something for nothing

[Deep Fried Geekboy]

The more potential focal points you want, the less resolution you can have for any particular one of them. You have to record information for all possible focal points on the CCD. Conceptually it's no different from, say, dividing the CCD into four parts and recording an image with a different focal point on each of the quarters, then post processing to combine them as required. I think. So photographically speaking the image is degraded compared to just getting the focal point right in the first place. Which isn't to say there aren't cool things you can do with it.

Re:innovation

[RedWizzard]

As soon as I heard of this, I immediately realized how to do it. But I would not have thought to do it on my own. This kind of smart thinking is why we have a patent system. The patent system was not designed to protect business methods, such as completing a sale using n clicks instead of n+1.

The patent system is not meant to protect an idea either. It's meant to protect a non-obvious implementation of an idea.

You don't really lose resolution

[mrmojo]

I'm one of the guys who works on this stuff at Stanford. I should point out that it's not fair to say you lose resolution, because good cameras have large pixels to reduce noise over a finite exposure time. Lightfield cameras, because they add up a whole lot of individual pixel samples to produce an image pixel, can get away with much much smaller pixels, because the noise goes down as you sum up the pixel values.

The best way to think of it is take a standard good quality camera with big pixels, subdivide each pixel into a grid of 12x12 or so tiny pixels - more like the size of pixels in cell phone cameras - and put a microlens over it. You get the same spatial resolution as the good camera, roughly the same noise characteristics, and the ability to refocus and pull other light field tricks like hitchcock zooms.

You just have to be aware that treating the data as a light field it's very noisy, like a crappy cell phone camera, but when you add up pixels to make a focused image, the noise drops back to regular good camera levels.

It's just harder to deal with the amount of data you get off a large sensor with tiny pixels, and they're also harder to build, but neither point is a showstopper and these are mere engineering issues...