Quantization to 256 colors with none/Riemersma error dithering

256 Colors	256 Colors + Riemersma
Uniform (3,3,2)
RMSE 31.706	RMSE 42.044
Popularity (5 bits)
RMSE 13.986	RMSE 25.142
Median Cut (8 bits)
RMSE 8.169	RMSE 12.504
Octree (8 bits 2-pass)
RMSE 8.135	RMSE 12.217
Xiaolin Wu v2
RMSE 6.825	RMSE 10.480
Dennis Lee v3 (5 bits)
RMSE 6.687	RMSE 10.591
Binary Split
RMSE 6.802	RMSE 10.692
Lloyd (K-Means)
RMSE 6.504	RMSE 10.421
NeuQuant (200 cycles)
RMSE 6.728	RMSE 10.680
SColorQ
NA