Place logo on Top layer in Altium
This is the wrong way to go. What you should do is the following:


Use a font creator tool to generate a custom font in TTF format (e.g. Font Creator)
One of the characters is your logo in a vectorized format
Then use a string field on your PCB and type one character (which stands for your font)
Select your font and you should see it being displayed nicely.


For an example look at the "Mooretronic" font. This font contains symbols for all kinds of stuff (ESD protection, Logos, ...).

We do designs for various customers and have a font with all their logos so we can just select which one we need. This way, it's also easy to remove soldermask on top of it so the gold surface can shine through (sorry, don't know how to explain that in english :-) )