Mostly just adding this post so I can easily find this awesome tutorial on PNG (a type of image format) optimization for the web (By Sergey Chikuyonok) when needed.
It gives an overview of what exactly is a PNG file including detailes on Scanline filtering and Image type, then offers tutorials on four techniques for optimizing your PNG image:
- 1. Posterization
- 2. Dirty Transparency
- 3. Split by transparency
- 4. Influence masks
While these would be overly time consuming to use on every little thumbnail in a project, it’s well worth putting in the time for say a header or background file that may be viewed by every site visitor for months or years to come. Right now I’m using the techniques for Sheridan Loudon’s Acupuncture for Harmony.com site here in Pensacola.