Refocusable Plenoptic Light-Field Photography 236
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."
oh so 1996 (Score:5, Informative)
"Say Sayonara to Blurry Pics"??? (Score:3, Informative)
This technology doesn't do anything to prevent camera shake. Most modern cameras are extremely good at autofocusing on the correct subject in a short depth of field situation. The camera designed by the Stanford guys is an amazing invention and will revolutionize action, sport, and scientific photography (especially at the macro level) but it will do nothing special for the consumer who simply doesn't understand that the longer the exposure the more likely the blur from camera shake.
Re:3d Images (Score:3, Informative)
Some other info from MIT (Score:1, Informative)
Re:"Say Sayonara to Blurry Pics"??? (Score:4, Informative)
Can't get something for nothing (Score:5, Informative)
Re:innovation (Score:5, Informative)
Re:innovation (Score:4, Informative)
Re:Just like in movies and TV! (Score:3, Informative)
Re:"Say Sayonara to Blurry Pics"??? (Score:4, Informative)
More like oh so this past summer at SIGGRAPH 2005 (Score:3, Informative)
You don't really lose resolution (Score:5, Informative)
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...
Re:"Say Sayonara to Blurry Pics"??? (Score:4, Informative)
The microlens approach doesn't require any moving part, it allows not only to refocus but also to extend focus as if one were using a very high F-stop for large depth of field, without the associated noise due to low light.
The downside is that it requires many pixels to produce a good image, but as the pixel count grows exponentially with time as per Moore law, it will soon be a winning proposition, even with cameras in mobile phones.
On the other hand optical stabilization is as expensive as ever, requires many moving parts and does not allow focus extention.
Re:You don't really lose resolution (Score:1, Informative)
Re:Just like in movies and TV! (Score:3, Informative)
Re:Just like in movies and TV! (Score:3, Informative)
I wonder about the effect on resolution and sensitivity of this technique. Modern autofocus on little point and shoot cameras is pretty good at what it does... a lot of blurry pictures are due to camera shake because poor lighting requires long exposure times. The article even mentions "poor lighting" although it somehow assumes that this technique will fix that too.
Re:X-Ray enhancement? (Score:4, Informative)
Medical X-ray photographies are simply taken by placing film (or these days a digital detector) behind the body and lighting with X-rays. No focussing is involved.
Re:Just like in movies and TV! (Score:2, Informative)
No, you can't, and you're completely right about that. But in the out-of-focus picture all the information is (mostly) there, and the question is how to transform that desired subject in focus. If you have the convolution model, you can write an inverse function using Fourier transform. For a quick mathematic formula, see here [uiowa.edu] and scroll a little down until you find section "Wrong lens focus". There's also software [focusmagic.com] that does the trick. The downside here is that it increases the noise as you can see on the focusmagic examples, but nevertheless it's possible and already done. The original work that represents the degradation model is from the 60's.