100% Image quality in wordpress medias

How to stop compressing JPEG Files

If you want WordPress to stop automatically compressing image, you need to tell it to load these files at 100% quality.

Add the following snippet to your theme’s functions.php file, or search the string add_filter through theme files and add to a proper location:

add_filter( ‘jpeg_quality’, create_function( “, ‘return 100;” ) );

This snippet will completely disable JPEG compression on your site in future, so for already uploaded you will need to run regenerate thumbnails plugin.

After a while, I saw that:
PHP Warning:  create_function() expects exactly 2 parameters, 1 given in /var/www/userland/it/wp-content/themes/clean-retina/library/functions/functions.php on line 136, referer: http://userland.kione.de/it/wp-content/themeCustomization/customEm.kione.css
And further searchings lead to that snippet:

add_filter( ‘jpeg_quality’, ‘jpeg_full_quality’ );
function jpeg_full_quality( $quality ) { return 100; }