Case in point, your explanation on tiling. How long does it take you to go through those steps? Wouldn't it be much easier just to open up Pov-Ray, edit one filename in the code listing to follow, and then render to a 256x256 image?
Change "Nuttz.bmp" to what ever image you are trying to tile. Yes, you still have to reduce the color count.
#version 3.1;
global_settings { max_trace_level 75 assumed_gamma 1.5 ambient_light 0
radiosity { brightness 1 count 300 distance_maximum 1 error_bound 1
gray_threshold .5 low_error_factor 1 minimum_reuse 1 nearest_count 1
recursion_limit 1 } }
#include "Colors.inc"
#declare TilePigment = pigment { image_map { sys "Nuttz.bmp" } frequency 1.2 phase 0 lambda 2 omega .5 turbulence 1.67 }
light_source { <-500,500,-350> color rgb 5 } //5*<.65,.46,.1> }
#ifndef (TilePigment)
#warning "No TilePigment specified. Pigment not tiled.\n"
#else
#ifndef (TileSize) #declare _TX_size = <1, 1, 1>
#else #declare _TX_size = TileSize * <1, 1, 1> #end
#declare _TX_xpigment = pigment {gradient x pigment_map {
[0 TilePigment scale <1 / _TX_size.x, 1, 1>]
[1 TilePigment scale <1 / _TX_size.x, 1, 1> translate x]}}
plane {z, 0 pigment {gradient y pigment_map {
[0 _TX_xpigment scale <1, 1 / _TX_size.y, 1>]
[1 _TX_xpigment scale <1, 1 / _TX_size.y, 1> translate y]}}
finish {ambient .45}}
camera {location <.5, .5, -1> look_at <.5, .5, 0> orthographic up y right x}
#end