I want to generate mipmaps for 2D textures as an offline step. My priority is for image quality, execution time is not a concern. The images will, naturally, always be halved and will always be powers-of-2.
I've found this fine article on the subject, which was helpful, but I don't have much knowledge on filtering, so I'm not very sure where to start.
I'm looking for algorithms and hopefully some sample implementations that I can base myself on. Also, using a third party library is an option, as long as it is open source and portable C or C++.
Any help is appreciated.