I've used the awesome RIOT tool for years now to optimise the map tile images used for http://www.topomap.co.nz but would like to incorporate the png optimisation into bat a script to make it more hands-off.
I've done some experimentation but just don't seem to be able to achieve the same levels of compression at the same quality as I can achieve through RIOT.
Can you please let me know what optipng settings might allow me to achieve the similar results?
These are the settings I use in RIOT under batch mode: imgur.com/a/4U79UA5
(this is using v0.4.6 as I encountered issues with batch processing in newer versions - luci.criosweb.ro/riot/bbpress/topic.php?id=471 )
And this is my best guess at optipng command line settings to use:
for /r %f in (*.png) do "C:\optipng-0.7.7-win32\optipng.exe" -o3 -nx -strip all "%f"
Any pointers or suggestions?