In Joomla 1.5 - 1.7, you could set up the overlays element to also use the file's extension for the value.
<field name="image" type="overlays" default="none" preview="true" path="__TEMPLATE__/images/backgrounds/" extension="true" label="BACKGROUND_IMAGE" />
Settingmeant the fields value would be saved as image1.jpg, instead of image1
But this is seemingly not working under Joomla 2.5 and later versions of Gantry? Am I missing something? Something changed? Because that exact XML works peachy in Joomla 1.7, but not in Joomla 2.5
Please advise.