MipmapGeneration

References

• Jon Blow articles in Game Developer Magazine:

  • Mipmapping, Part 1
  • Mipmapping, Part 2

• Non-Power-of-Two Mipmapping

Conclusions

Here are some of my findings:

• Windowed sinc filters with radius greater than 3 produce too many ringing artifacts.
• For good results with non power of two textures or arbitrary scales, you must use polyphase filters.
• Sampling the polyphase filter with a box filter greatly improves the quality.
• Using a triangle filter looks even better, but the difference is small.
• For most cases box does a great job.
• The Lanczos and Kaiser windows produce indistinguishable results.
• Gamma correction produces more correct results, but sometimes enhances the ringing artifacts.

More stuff:

• For HDR images box filters work best, the higher the discontinuities the higher the ringing artifacts.