(PECL imagick 2, PECL imagick 3)
Imagick::equalizeImage — Equalizes the image histogram
Equalizes the image histogram.
This function has no parameters.
   Returns true on success.
  
Throws ImagickException on error.
Example #1 Imagick::equalizeImage()
<?php
function equalizeImage($imagePath) {
    $imagick = new \Imagick(realpath($imagePath));
    $imagick->equalizeImage();
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}
?>