一种复合型图像加减滤波器

A Composite Filter for Addition and Subtraction of Images

介绍了一种复合型图像加减滤波器，该元件是由Ｒｏｎｃｈｉ光栅和离轴Ｆｒｅｓｎｅｌ波带板复合而成，它的透射率函数是Ｒｏｎｃｎｉ光栅和Ｆｒｅｓｎｅｌ波带板两透射率函数的逻辑异或。用作图像加减时具有光路简单、调节方便、处理的面积大等优点。讨论了用这种滤波器作图像加减的原理，介绍了元件的制作方法．并给出了实验结果。

In this paper, we introduce a composite filter for addition and subtraction ofimages. The filter consists of a Ronchi grating and an off-axis Fresnel zone plate. Thetransmission function is logic XOR operation of the Ronchi grating function and the Fresnelzone plate function. This method for images addition or subtraction has some advantages ofsimple optical setup, convenient adjusting and capability of processing large images. Theprinciple of images addition and subtraction of using this filter is discussed. The fabricatingmethod and the experimental results are reported.