As I recall, you're fairly handy at scripting, so
this 'heavens.php' contains an example of just this sort of manipulation.
You can follow this variable to see what happens to it:
$pc_cacheFile = './cache/heavenpie.png'; // Relative path and name of cached image file
You can save the image in different formats, gif, png, or jpg by using the appropriate php function: imagegif(...), imagepng(...), or imagejpeg(...).
Hope this helps.
BTW, with '
firedangerWD.php' I've taken the opposite approach by using AJAX to update the image on my alternate dashboard in real time.