(PECL imagick 2.0.0)
Imagick::compareImageLayers — Returns the maximum bounding region between images
Compares each image with the next in a sequence and returns the maximum bounding region of any pixel differences it discovers. This method is available if Imagick has been compiled against ImageMagick version 6.2.9 or newer.
Returns TRUE on success.
Throws ImagickException on error.
Exemplo #1 Using Imagick::compareImageLayers()
Comparing image layers
<?php
/* create new imagick object */
$im = new Imagick("test.gif");
/* optimize the image layers */
$result = $im->compareImageLayers(imagick::LAYERMETHOD_COALESCE);
/* work on the $result */
?>