Contrast
Change the contrast of an image. Contrast is the difference in luminance or colour that makes an object distinguishable.
Parameters
amount
The amount of contrast to apply. >= -100 and <= -1 to reduce. 0 for no change. >= 1 and <= 100 to increase.
Examples
use Grafika\Grafika; // Import package
//...
$filter = Grafika::createFilter('Contrast', 50);
$editor->apply( $image, $filter ); // Apply it to an image
Test image:

Result:
