Wednesday, November 12, 2008

Quick PNG Raster Compression Comparison

After reading this blog entry about using PNGNQ which I have also been using,I thought it would interesting to do a quick and dirty comparison

All images where created just using the default command line options,

i.e. util.exe filename.png

Imagery was sourced from

MapGuide PNG32 2.0.2  138.174 Kb NQ8 pngnq 0.5   56.055 Kb
NQ8+pngcrush 1.6.10   49.762 Kb NQ8+OptiPNG 0.6.1   49.420 Kb MapGuide PNG8 2.0.2   38.728 Kb

It turns out that MapGuide comes out on top in when configured for PNG8 :)

Now if only the GDAL FDO provider was stable...


Anonymous said...

Hi, can you please point me to the algorithms MapGuide is using to optimize PNG8 to this form?
Will it correctly convert true alpha channels (not only two/state) as well?

Klokan Petr Přidal said...

I mean images like this: