参考资料来自：
https://booksite.elsevier.com/samplechapters/9780123814203/Woods_3.1_through_3.3.pdf
和
Poularikas A. D. "Two-Dimensional Z-Transform"
The Handbook of Formulas and Tables for Signal Processing.
Ed. Alexander D. Poularikas
Boca Raton: CRC Press LLC, 1999
定义
逆变换
与F-t的关系
性质
System Function
