中文摘要：

大的焦深在光学显微镜,生物和医学成像,微电子学,红外光学系统,虹膜识别等高端成像系统以及摄像头等低端成像系统均能发挥重要的作用。因此人们一直致力于研究如何能拓展焦深并据此提出了许多方法。本文将介绍几种比较成熟的焦深延拓方法。

英文摘要：

Large depth play an important role in the advanced fields such as optical microscopy,medical or biological imagery,microelectronics,infrared optical system,iris recognition system etc.and the basic field such as camera.Therefore,people have been working on the way to extend the depth and proposed many methods,In this paper we will present some mature methods of extending the depth in details.