Brightness
Change the image brightness.
Parameters
amount
The amount of brightness to apply. >= -100 and <= -1 to darken. 0 for no change. >= 1 and <= 100 to brighten.
Examples
use Grafika\Grafika; // Import package
//...
$filter = Grafika::createFilter('Brightness', 50); // Apply a brightness of 50.
$editor->apply( $image, $filter ); // Apply it to an image
Test image:

Result:
