Hmm ok better talk about texture mapping then. This is where you take a raster image and apply it into a vector space which is usually a 3D polygon for 3D models but it can also be a vector 2D area too.

What its essentially doing is resampling the raster texture but its not doing it with fixed scaling, the scaling is selected per pixel based on the vector shape so you can texture map a rectangular photo onto a circular disk for example. You can control the circle shape in a vector way and the image inside is a raster photo conforming to the shape of the circle.

I believe this is what Xara does and is what my ViewingDale does which allow both apps to scale up stuff using photo textures in a kind of vector way. In my opinion tho texture mapping is more of a raster process than a vector one. If you conform a low res photo into a shape and make that shape big then you will get the pixels showing up. If the photo was truly vectorized, which Xara can do very well too, then it would scale up perfectly but as said earlier it has to limit the colors and vectorize the bands within that photo instead of the full range of colors. So theres several options available but its just worth familiarizing yourself with all the options.