Feature: try to auto detect compression-quality

[voku]

Hi, I like your image-optimizer-wrapper for PHP and maybe you find some useful lines of code here: https://github.com/voku/dotfiles/blob/master/bin/img-min.sh

The quality-detection works for JPEGs (https://github.com/voku/dotfiles/blob/master/bin/img-min.sh#L108) and for PNGs, but for PNGs there is also an quality-range-setting for pngquant (https://github.com/voku/dotfiles/blob/master/bin/img-min.sh#L74).

PS: here you can test the script: http://image-api.suckup.de/

[gtuk]

Good suggestion, i will take a deeper look on that feature in the next weeks