Highcharts image export with PhantomJS. More info on: http://www.highcharts.com/component/content/article/2-news/56-improved-image-export-with-phantomjs

save_chart.php

<?php

public function action_save_chart() {

    $string = <<<EOD
{"infile":"{credits:{enabled:false},xAxis:{categories:['Jan','Feb','Mar']},series:[{data:[29.9,71.5,106.4]}]}"}
EOD;
    
    $ch = curl_init('http://127.0.0.1:3003');
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");            
    curl_setopt($ch, CURLOPT_POSTFIELDS, $string);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);                                                                      
    curl_setopt($ch, CURLOPT_HTTPHEADER, array(                                                                          
        'Content-Type: application/json',                                                                                
        'Content-Length: ' . strlen($string))                                                                       
    );
    
    $base64string = curl_exec($ch);
    file_put_contents('img.png', base64_decode($base64string));
}

?>