Drizzling (spin off from dithering)

[Carole]

This is going to confused Doug once again, sorry Doug.

So can some-one explain drizzling please. 
What is it, what does it do and how do you do it?

Carole

[mickw]

It's all here

http://en.wikipedia.org/wiki/Drizzle_(image_processing)

[MarkS]

The original paper by Fruchter and Hook is here:
http://www.stsci.edu/~fruchter/dither/drizzle.html

Craig Stark has writen a good article here:
http://www.stark-labs.com/craig/articles/assets/Drizzle_API.pdf

For Chris, here is a quote from that article:
"The fact that undersampled stars look blocky cannot be avoided. What Fruchter and Hook demonstrated in Drizzle was that we can exploit the fact that small motions of the stars – even fractions of pixels – make the stars look blocky in different ways each time to reconstruct higher resolution images. That is, we can use the "dither" or random noise in the location of the stars with respect to the CCD array in conjunction with many images to reconstruct an image that is higher resolution than our CCD array itself."

DeepSky Stacker, IRIS, Registax and other software can all perform Drizzle.

Mark

[The Thing]

Very interesting, shame I've got an 8" SCTand so little chance of exploiting it (I read Mr Starks' article).

[mickw]

I noticed the ad for CCDWare on Starks article and had a rummage, all the software looked excellent so I thought I'd give them a try - Then I found the pricelist 

[Carole]

Oooow, lots of things to study when I get home.

Thanks

Carole

[doug]

     Yeah, Carole................... confusion rains ..(drizzle???)   

     Doug.

[MarkS]

     Yeah, Carole................... confusion rains ..(drizzle???)   

That's right Doug - I think you've understood it.  It's called drizzle because the data from the camera exposures (on a coarse pixel grid) "rains down" onto the subsampled output image (on a fine pixel grid).

Mark