Wednesday, February 08, 2006

Enhance

So I'm watching a lot of CSI lately. Primarily Las Vegas. The other night on the show, Nick Stokes was looking at a photograph on the computer. They were using one of those magic computers that they have over there at the lab so they were able to zoom in sooooo closely on the eye of the person in the picture that they could see the image in the the reflection on the eye.

Now something about that always bothered me because I just can't understand how you can keep turning these big pixels into sharp lines. "Thats Impossible!" I would shout at the television. How can they do it? I wonder if it's technology that is just beyond my understanding. Well, I guess I'm starting to understand how it might possibly work, under the right circumstances.

They seem to be using a method called Interpolation to enhance the image. It actually gives a more accurate representation of the image the camera was attempting to capture.

I learned a few things at Smart Guy's Website about the algorithms they use to process these images and enhance them.

" The various algorithm's then divide the original large pixel into a number of smaller pixels whoose new values are derived (interpolated) from the shared values of the original adjacent pixels. Bilinear Interpolation multiplies the original pixel into four, Dipietro and Molenaar's S.P.I.T. multiplies it into eight, and the "Cubic Spline" method used by Carlotto uses twelve surrounding pixels.

This is, in effect a statistical analysis of the data provided by the pixel relationships. "


1 comment:

Fitech said...

I found another website with some great explanation.

Link

The more I learn, the more I think it would be impossible to zoom in on the reflection in someone's eye when the original picture resolution is just not that good.