Quote:
Originally Posted by avandonk
My image scale is 3.08" per pixel.
I do understand information theory. Farting around with a single image is meaningless.
I dither my images by many pixels. This means I am sampling the same putative image many times.
I typically collect twenty plus images.
Bert
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Well, the web reference is useful to explain the main concept of drizzling for those that may not be familiar with how it works. I believe it(drizzling) was used on the Hubble deep field images to regain much of the resolution that is lost due to the undersampling by the WFPC2 camera.
As you imply though, our actual images won't replicate this exact outcome; I believe due mainly to random dithering, high freq noise, limited sub frames available, etc. I'm also not clear to what extent the SNR would suffer (per output pixel) since (as I understand it) drizzling is a process that "constructs" a higher resolution image from multiple (lower res) subframes, whereas with simple stacking of n subframes (using say the mean on the original pixels) the SNR is increased by sqrt(n). I assume that for sufficient sub frames there will also be some "stacking" of the drizzled image output pixels which will increase the SNR at the higher res pixel size?
So ... given that your system is undersampled it would be very interesting to compare upsized/stacked vs drizzled images from the same set of sub frames if you ever have the opportunity. I believe that drizzle is being incorporated into some of the popular software and may also be available standalone.