[KUROK]

Hi,

I remember a while back someone out here posted a screen shot from "Tholian Web". It was three frames that had been averaged and this produced a really clean image. What I'm asking for is which software applications will do this image average function. Which is best and which is least expensive?

Thanks!

 

[TrekFX]

I used Photoshop for that. The technique is called "stacking" and is popular in astrophotography.

Any program that will let you add layers and adjust their opacity will work. To align the images perfectly, I start with the new layer mode as "difference" and move the layer around until it goes all black. Then switch back to Normal, change the opacity to 50%, and merge the layer and background. Do this as many times as you can stand!

 

[Pygar]

I saw a thing on the Net once called Panotools, which had a dedicated image averager and was free.

 

[uss_columbia]

I had read that NASA used multiframe deconvolution techniques to enhance images from Hubble, for example. It was my understanding that complicated math was involved not mere pixel averaging. This was due, I think, to the slight motion (or vibration) between frames. I guess if the multiple shots are of the exact same position, just averaging would work. TrekFX's method aligning the images before mixing them sounds good.

In general, it seems averaging multiple samples will reduce the noise but will not increase effective resolution. However, combining images where there is motion can increase effective resolution (as is done with the Hubble images). You could probably do the same thing (manually) with a variation of TrekFX's technique:
(assume motion is at least 1/2 pixel)
- enlarge all images by 100%
- now move them to get the best possible alignment
- now average them
result is an image with twice the effective resolution of any of the originals

 

[John P]

One of my coworkers got us a program called "Extensis pxl SmartScale" It's suppose to take lo-res internet jpgs and enlarge them, interpolating and adding pixels to clarify the image as it gets bigger. I've only used it a couple of times, but so far i don't see anything I can't do in Photopaint by increasing DPI while enlarging and using the "soften" function.