On Thu, Feb 6, 2014 at 10:17 AM, Robert R. Raiz <raizrobert@gmail.com> wrote:
I also noticed that the output of the png files is PNG32. I should be able to maybe reduce those as well (their size), especially on the tiles that have many pixels of the same color.

pngcrush or optipng or something similar should be run on all PNG files intended for the web, but even then you will probably find there are too many colors (more than 256) and intermediate alpha levels.  At least try explicitly running an option to reduce the number of colors in the image to 256 using a program that dithers the output where necessary.  Most image processing programs should be able to do this, though how well they do it is highly variable, and what happens to the alpha channel can be unpredictable.

Make sure you use something the produces an optimized palette when reducing colors - some programs use a standard palette (often described as the 'web palette') and that is unlikely to work well for your data.

John Bowler