Button for Directory Opus that will compress a PNG if compression is possible and replace the PNG. Rexuires pngquant in PATH.

Compress PNG images with pngquant.XML

<?xml version="1.0"?>
<button backcol="none" display="label" textcol="none">
	<label>Compress PNG images with pngquant</label>
	<tip>Will overwrite your file if compression is possible make a backup please</tip>
	<icon1>#newcommand</icon1>
	<function type="batch">
		<instruction>@echo off</instruction>
		<instruction>:start</instruction>
		<instruction>pngquant.exe 256 --force --ext .png --quality=50-90 --ordered --speed=1 --strip --skip-if-larger {file}</instruction>
		<instruction>shift</instruction>
		<instruction>if NOT x%1==x goto start</instruction>
	</function>
</button>

Nice, thanks for this!