Thank you guys very much for your suggestions!!!
@Nic That look pretty promising, but I have nearly zero experience with Lua and no clue on how to mix it with C (cuz my project is written in C). ;'D
So, I chose another obvious and easy solution, and I don't know why didn't see that in first place. >_<
I work now with pd->graphics->drawScaledBitmap() and it works pretty good!
But again, thank you all for your ideas! 