allowedExtensions

allowedExtensions
Path:$GLOBALS[‘TCA’][$table][‘columns’][$field][‘config’]
Type:string (list of file extensions)
Scope:Proc. / Display

List of image types (by file extension) which can be cropped. Defaults to $GLOBALS['TYPO3_CONF_VARS']['GFX']['imagefile_ext'] which is usually gif,jpg,jpeg,png.