Filter suggestion improvement #505
Description
I met with @bitbank2 who mentioned this.
§ 12.7 Filter selection says "For images of color type 3 (indexed-color), filter type 0 (None) is usually the most effective." This isn't necessarily true. Filter selection is very situational.
The 'up' filter is quite effective on indexed images with large swaths of solid colors, such as logos.
We should improve our suggestions.