Removing Image Noise

BillyBoy wrote on 5/29/2003, 4:16 PM
One minor weakness Vegas has is no included power tools to remove image noise directly. Yes, I know, some of the FX filters can blur or mask it somewhat but not really remove it. Sure you can use VirtualDub and there are several filters that work well with it, but sometimes you want more. I ran across this article while surfing looking for something else and thought others may find it useful too.

Somewhat biased but still interesting discussion of various applications that can do a pretty good job of cleaning up noisy video.

http://www.michaelalmond.com/Articles/noise.htm

Comments

JJKizak wrote on 5/29/2003, 6:50 PM
If SOFO could come up with a killer video noise reduction plugin that would put
many daggers into the competition, that is if it worked.

JJK
farss wrote on 5/29/2003, 7:29 PM
I have always thought it should be possible with video not only to reduce noise but also increase resolution. Across each sequence of frames is stored muliple images of the same thing. By firstly corelating the objects within each frame and then looking for the non random noise it can be removed. Alternatively resolution can be enhanced.

I some time ago found a doctoral thesis on this type of technology, the results looked pretty spectacular.

However it would require some very sophisticated software and the processing time would have to be enourmous. It also may not be possible to produce consistent results without a lot of human intelligence to guide the process.

I'd imagine the spooks have something with this sort of capability, just how applicable it would be for day to day video I don't know.
johnmeyer wrote on 5/29/2003, 10:41 PM
Eric Chen, founder of Reality Studio that made Photovista stitching and many other programs, also had a similar idea of using multiple frames to increase resolution, in essence trading temporal for spatial resolution.

Back to the original topic, for now, I'm using PluginPac to access various noise reduction tools available for VirtualDub. They work pretty well to average pixels across frames, and thus reduce random noise. The kNRC plugin is one that I'm currently using quite a bit because it averages pixels in adjacent frames differently depending on their luminosity. This seems to result in fewer artifacts.