(PECL imagick 2 >= 2.1.0, PECL imagick 3)
Imagick::mergeImageLayers — Merges image layers
   Merges image layers into one. This method is useful when working with image
   formats that use multiple layers such as PSD. The merging is controlled using
   the layer_method which defines how the layers are merged.
   Questo metodo è disponibile se Imagick è stato compilato con ImageMagick versione 6.3.7 o successive.
  
Returns an Imagick object containing the merged image.
Lancia una ImagickException in caso di errore.
Example #1 Imagick::mergeImageLayers()
<?php
function mergeImageLayers($layerMethodType, $imagePath1, $imagePath2) {
    $imagick = new \Imagick(realpath($imagePath));
    $imagick2 = new \Imagick(realpath($imagePath2));
    $imagick->addImage($imagick2);
    $imagick->setImageFormat('png');
    $result = $imagick->mergeImageLayers($layerMethodType);
    header("Content-Type: image/png");
    echo $result->getImageBlob();
}
?>