src/Utilities/MimeTypes.php
public static function isImage($mimeType)
    {
        if (in_array($mimeType, self::$mimeTypes, true)) {
            return (bool)preg_match('|^image/.+$|', $mimeType);
        }

        return false;
    }
public static function isImage($mimeType)
    {
        if (in_array($mimeType, self::$mimeTypes, true)) {
            return (bool)preg_match('|^image/.+$|', $mimeType);
        }

        return false;
    }
public static function isImage ( $ mimeType ) { if ( in_array ( $ mimeType , self :: $ mimeTypes , true ) ) { return ( bool ) preg_match ( '|^image/.+$|' , $ mimeType ) ; } return false ; }
Returns information whether the given file type is an image

@param string $mimeType The mime type of file
@return bool
Returns information whether the given file type is an image