I have trying hard, but can't make this method works properly.
The usage format is

Imagick::levelImage ( float $blackPoint , float $gamma , float $whitePoint [, int $channel = Imagick::CHANNEL_ALL ] );

Ben gibi kullanabilirsiniz deneyin

$img->levelImage (0, 1.0, 255);

ve

$img->levelImage (255, 1.0, 0);

hatta gibi

$img->levelImage (-0.5, 1.0, 5.6);

but without any success.
Output image is either almost black or almost white.
All other imagick methods I use work fine, but this one is just a back-breaker for me))
I can't find any examples of usage this imagick method on the net so need help!
Maybe somebody have an good working example, help me please:)