I would like to use Inkscape as a screenshot illustrator (image editor). I have a bitmap, a software interface capture for example, and would like to draw some vector objects over it. However I can't find the proper zoom level to display the bitmap properly (at 100% or 200% it randomly works, it depends of the screenshot size) and more important, export it so the result is not "jagged". The zoom level, even at 100% (1:1) is never correct as Inkscape doesn't consider the canvas as a bitmap, as The GIMP does for example, but as vector. The only solution I found is to set the exported bitmap dimensions to 90 ppp but I'm not sure it works in all cases. I don't even know why 90 works, I suppose it balances the bitmap/vector ratio.
I guess I'm looking for some sort of hybrid mode between bitmap and vector image editing.