high_way

i was wondering if anybody could explain to me the difference between interpolated and extrapolated pictures?

i am looking at getting either a web cam that can take still or a digital camera and i was wondering which was the better quality to get?

any help would be appreciated.

__________________
A stranger is just a friend you havent met yet.

Impostor of the imposturous

Scorpion23

Well, by definition interpolated means to create a point by using data from the pixels that surround that point. In a picture this would give you higher resolution from an original photograph.

Extrapolation is creating a point by using information contained in pixels which are not surrounding that point.

If * is the new point and + are the originals, then it would look something like this:

Plain:
+ + + + +

Interpolated:
+*+*+*+

Extrapolated:
*+*+*+*+*

Interpolation gives you a high quality, high res image while extrapolation gives a higher res image at the cost of quality.
This is because it has to guess on some points where interpolation has plenty of data to work with. The math in the good programs is insane, so i'm not even going to try and explain it. Bottom line is that interpolation gives the highest quality, but it also depends on the quality of the software.

__________________
"Empirically observed covariation is a necessary but not sufficient condition for causality" - Edward Tufte

jujueye

Hi! You might try to search a bit on http://www.dpreview.com. This is a digital camera site that does reviews. I'm sure somewhere in their reviews they will explain which is better or worse.

cheers!

high_way

thanks for the info scorpion, gives me a better idea. thanks for the website jujueye checking it out now.

__________________
A stranger is just a friend you havent met yet.

Impostor of the imposturous