Get free image for commercial distribution google : i would like to get image using Google api in my app, i want to get, based on some keywords, only free image for commercial use, is it possible? Have i to Credit Google? Or image owner? Can i download the image?

<code>foreach ($images as $i) {
    $image = rawurlencode($i);
    $query = "https://ajax.googleapis.com/ajax/services/search/images?v=1.0&q=".$image."&imgsz=large&as_filetype=jpg";

    $json = get_url_contents($query);
    $data = json_decode($json);
    $results = array(); //define array here!
    foreach ($data->responseData->results as $result) {
        $results[] = array("url" => $result->url, "alt" => $result->title);
    }

    echo $results[0]['url'];
    echo "<br />";
    echo $query;
    echo "<br />";
}</code>