I'm 90% of the way to what I'm trying to do.  I have an exported SVG from another program that is white vectors over a black and white raster image (black background, white lines/foreground in that raster image).  I want to invert the whole thing so it appears to be black lines on white paper.  If I select it all and FILTERS>COLOR>INVERT it flips correctly and my vectors remain vectors.  If I SAVE-AS as a pdf, though, if I don't select rasterize filters then the exported pdf opens in external viewers as the original black background image.  If I DO select rasterize, it opens externally as a white background, but the ENTIRE image is now rasterized and loses resolution when zoomed.  Here's the oddball though:  If, after applying the invert, I simply save the SVG again and reopen THAT SVG in MS Edge for instance, it opens as white and the vectors are intact...  but if I export as a pdf from there, it rasterizes again.  What workflow can I follow to invert this image and get it to a pdf while retaining the vectors?  I don't care if the already-raster background gets fuzzier, but I need the resolution in my vectors to remain.