"Drizzle" ? Looking for new processing techniques.

[rogerg (Roger)]

G'day all,

I'm looking to maximise the detail I'm getting from a very small image area(about 200 x 200 pixels) from a deep sky image. I'm very familiar with the usual reduce, align & combine techniques using average, median, add, etc. However I have heard the term "drizzle" used and I'm wondering what this is, and if it's applicable then how I can do it?

I'm really wanting to push detail out of this small image area so am looking for new techniques.

Thanks for any tips.

Roger.

[rmcpb (Rob)]

Drizzle is the technology used by the Meade imagers where it automatically stacks images on the fly and builds up the image automatically.

That's about all I know about it.

Cheers

[ving (David)]

hmm... registax has a drizzle checkbox.

[acropolite (Phil)]

I thought drizzle also had the capacity to stitch and stack images together on the fly to make an image larger than the sensor can normally deliver.

[rogerg (Roger)]

Hmm, well..

Ving appears to be closest to the mark on what I'm after. I didn't notice RegiStax had a Drizzle option. I've had success using it once then since then it's produced bizzar incorrect results - some setting seems to have got messed up.

Phil & Rob - This is interesting, it appears Meade has something called drizzle but I'm not sure it's the same. What they're doing sounds more like "track and accumulate" type stuff ?

Drizzle in the form I'm looking for it is a processing technique which usually results in a larger resolution image with more detail than the original individual exposures of a smaller resolution. I don't understand how, after having read an explanation on the web about 3 times.

I believe IRIS does have a Drizzle function but I haven't re-installed that yet to work out if it does what I want, I haven't had much success with IRIS in the past. RegiStax appears my best bet sofar. Still looking and hoping for other options. I was disapointed to see RegiStar does not provide a drizzle function even though it has other combine algorithms.

Roger.

[ving (David)]

i had a play with drizzle in registax once... it resized the image. i couldnt really comment more on that tho unfortunately, except its in the same box as resampling

[JohnH]

Originally Posted by rogerg

Drizzle in the form I'm looking for it is a processing technique which usually results in a larger resolution image with more detail than the original individual exposures of a smaller resolution. I don't understand how, after having read an explanation on the web about 3 times.
Roger.

Meade's Autostar Envisage Software will drizzle either in real time (as it accumulates from a DSI or LPI) or as a post processing option - and yes it will yield a higher res image as a result than the native res of the imaging chip - to work properly the image must dither across the sensors pixels (ie tracking must not be perfect!) as it uses this movement to give you the res boost. I think of it being a little like anti-aliasing if that helps. Nebulosity also has this routine I believe and I think it is the same in Registax but I do not use that program much as it chokes on DSLR files - but that is another story....