Description
resource 
imagecreatefromstring ( string image )
   imagecreatefromstring() returns an image identifier
   representing the image obtained from the given string. These types
   will be automatically detected if your build of PHP supports them:
   JPEG, PNG, GIF, WBMP, and GD2.
  
Return Values
   An image resource will be returned on success. FALSE is returned if
   the image type is unsupported, the data is not in a recognised format,
   or the image is corrupt and cannot be loaded.