<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical">
    <mx:Script>
        <![CDATA[
       
       
        import mx.graphics.ImageSnapshot;
        import mx.core.UIComponent;
        import mx.controls.Alert;
       
        public function takeSnapshot(target:UIComponent) :void
        {
            var shot:ImageSnapshot = ImageSnapshot.captureImage(target);
            Alert.show(ImageSnapshot.encodeImageAsBase64(shot));
        }
       
       
        ]]>
       
    </mx:Script>

    <mx:Button click="takeSnapshot(targetPanel)" label="Save Image" x="10" y="100"/>
   
    <mx:Panel id="targetPanel" layout="vertical">
    <mx:Label text="Hello World"  y="9"/>
    <mx:Image  source="http://www.google.cn/images/nav_logo4.png"/>
    </mx:Panel>

</mx:Application>

<?php
$base64_string = "";
file_put_contents("test_1.png",base64_decode($base64_string));
?>