You can use it to optimize your png files in best quality. This package use imagemagick and pngquant; so you must install them first. You can optimize your images in any quality you want.
By default it will scan dir for finding png files in depth of 6 that you can change it very easy.
You can use it Only in One Line :

$statement->optimize($dir, $min_quality, $max_quality, $strip);
example1:

require_once './vendor/autoload.php';
use Parsaaghayi\Pngoptimizer\PngOptimizer;
$test = new PngOptimizer;
$test->optimize('../test/images',65,80);

This code will create an optimized version of your png file which the name is filename-fs8 in same directory
Original Image (799KB):

optimized Image (264KB):