Export Image @ Original Resolution ?

Is it possible to export a graded image at its original resolution, say 6000 x 8000px, from a 4K or even 1080p timeline?
Or would I need to create a temporary project / timeline at the image's resolution for that purpose?

All stills are grabbed at timeline resolution.
You could set up a still format for export on the Deliver Page and set to export at source resolution. It will work for a singe export but not if you need to export many stills.

I did not think of the fact that Resolve keeps the original resolution of all media up until export.

Your tip works out perfectly.
But when the original images proportions are not like the timeline, it is necessary to set scaling to "fit", set the export dimensions to those of the original image on the longer side and according to the timeline proportions, e.g. 16:9, on the other.

After exporting and cropping away the black bars, the graded image has the same pixel count as the original.

Thank you Peter.

what I do for those times I need to output multiple stills from a timeline is to copy the timeline and make it full res (mostly shoot 4k, work & deliver 1080) and grab my stills from there.
I have a client who I need to do this on a regular basis and works really well. My video timeline doesn't get mucked about and my stills are all full res.