PNG thumbnails don't retain transparency

[BillyHilly]

Hello, First off, LOVE YOUR PLUGIN. This is awesome. So minimal, yet it's all I need. That being said, I noticed the PNGs I upload that have a transparent background do not retain the transparent background on thumbnails produced. I think something simple needs to be set to detect the transparency and ensure thumbnails inherit it as well. Possibly something like:

$imagick->setBackgroundColor(new ImagickPixel('transparent'));

I'm not quite at your level to write this stuff, but I'm more than happy to keep using and testing your plugin to help it reach mythical CMS Image Manager Perfection status :)