CREATE OR REPLACE FUNCTION fn_split (p_str IN VARCHAR2, p_delimiter IN VARCHAR2)
RETURN ty_str_split
IS
  j INT := 0;
  i INT := 1;
  len INT := 0;
  len1 INT := 0;
  str VARCHAR2 (4000);
  str_split ty_str_split := ty_str_split ();
BEGIN
  len := LENGTH (p_str);
  len1 := LENGTH (p_delimiter);
  WHILE j < len
  LOOP
    j := INSTR (p_str, p_delimiter, i);
    IF j = 0
    THEN
      j := len;
      str := SUBSTR (p_str, i);
      str_split.EXTEND;
      str_split (str_split.COUNT) := str;
      IF i >= len
      THEN
        EXIT;
      END IF;
    ELSE
      str := SUBSTR (p_str, i, j - i);
      i := j + len1;
      str_split.EXTEND;
      str_split (str_split.COUNT) := str;
    END IF;
  END LOOP;
  RETURN str_split;
END fn_split;

create or replace function fn_ispng(
                     strpng  in varchar2
                     ) return number is
 v_num  number;
begin
   WITH t1 AS
  (select * from table (fn_split(strpng,'.'))
  )
 select count(1) into v_num from t1 where t1.column_value in ('png', 'jpg','jpeg','gif','bmp','eps');
 return v_num;
end fn_ispng;

select fn_ispng('dfdfd.png')   from dual;