SoftLayer_Hardware_Server::captureImage.php

<?php
include('softlayer-api-php-client/SoftLayer/SoapClient.class.php');
$apiUser = '';
$apiKey = '';

$serverId = ;

$serverClient = SoftLayer_SoapClient::getClient('SoftLayer_Hardware_Server', $serverId, $apiUser, $apiKey);

try {
    $result = $serverClient->captureImage();
    print_r($result);
} catch (Exception $e) {
    print $e->getMessage();
}