Using the combination of the mask and the post-processing software, MERL researchers were able to reconstruct a 4D light field from the standard 2D camera, explained MERL Visiting Scientist Amit Agrawal. Instead of bending light rays, the patterned mask attenuates the rays inside the camera. The post-processing software reconstructs the light field using an inverse computation of the Fourier transform equation, allowing the user to refocus the image.The article has a slideshow, including some sample images. For some reason, they seem a bit dull, a bit like the images taken with digital cameras from 10 years ago; I wonder whether this is a result of the image reconstruction algorithm.
That URL is completely wrong, although it's on a smilar topic.
It still relies on extracting a relatively low resolution image from an extrmely high resolution CCD, so I don't see it being particularly useful. Even if you want to play with multiply focussed images (have you seen Haeberli's work on that?: http://groups.csail.mit.edu/graphics/pubs/npar2004_imagefusion.pdf) it's easier to just take several images with your camera on a tripod.
This bit is particularly interesting:
Q. How do you print these masks?
For Coded Focus Camera, the broadband mask is a binary 7 by 7 pattern (49 holes, approximately half opaque and half transparent). The size of each hole is >1mm^2 (to avoid diffraction). This can be printed easily as a standard emulsion based transparency. Printing cost is cheap, one can get 20 of these masks printed on a single A4 size transparency for $50. For amateur photography, one can print the mask on a standard overhead transparency on home printer.