Quote Originally Posted by Jimmy Valavanis View Post
Do you think that a high quality scale algorithm (such as xBR, xBRZ ect) could help before making the transformation ?
I doubt it would help much if at all. Why? Because most scaling algorithms also utilize Anti-Aliasing for smoothing of the final result. Which as I described above could eventually make things even worse especially if you are doing transformation after rescaling.
I still think that the best bet would be to use vectorization. Why? Because after you turned raster image into vectoriozed one you can then do any kind of rescaling or transformation with little or no detail loss.

PS: If you are just interested in making a nice looking brick wall texture (which I doubt) I could give you a few hints on how to achieve that