The 'Reversed level adjustment' function isn't exposed as function in the ImageMagick library so isn't usable in Imagick.

Instead you can use the evaluateImage function to achive the same effect. Please see the levelizeImage tutorial.
Black point
WhitePoint
Gamma

The 'Reversed level adjustment' function isn't exposed as function in the ImageMagick library so isn't usable in Imagick.

Instead you can use the evaluateImage function to achive the same effect. Please see the levelizeImage tutorial.
function levelImage($blackPoint, $gamma, $whitePoint)
{
    $imagick = new \Imagick();
    $imagick->newPseudoimage(500, 500, 'gradient:black-white');

    $imagick->setFormat('png');
    $quantum = $imagick->getQuantum();
    $imagick->levelImage($blackPoint / 100, $gamma, $quantum * $whitePoint / 100);

    header("Content-Type: image/png");
    echo $imagick->getImageBlob();
}