The following function applies a callback to each image in an Imagick object.<?phpfunction imagickMap($callback, $im){ $im->setFirstIterator(); do { $callback($im); } while ( $im->nextImage() );}?>E.g. to convert a series of images to grayscale:<?phpimagickMap( function($im) { $im->setImageType(Imagick::IMGTYPE_GRAYSCALEMATTE); }, $im);?>