Quote:
Originally Posted by Atmos
If you haven't drizzled between each image then when you run them through a dithering process there is no difference between all of the pixels, won't make any difference. I think I am understanding you correctly; dithering a batch of un-drizzled images?
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You've got your terms mixed up there. Dithering is when you move the telescope between each sub-frame - its a process that is performed during image capture. After calibration and registration of your subs it allows you to stack signal only, and not fixed pattern noise. Drizzle however is an integration process, where pixels from registered sub-frames are mapped onto a smaller pixel grid. eg if the original sub-frames are width and height W x H, then the stacked 2x drizzle final image will have width and height of 2W x 2H.
It is
dithering between sub-frames that is required for
drizzle to work.
What I am trying to get at is what is the effect (with respect to both Ray's original formula and to the resulting resolution of the final image) of performing:
1) a 2x drizzle integration on dithered sub-frames that were captured with 2x2 binning, compared with
2) integration (without drizzle) of dithered sub-frames that were captured with 1x1 binning