Nowadays, the image processing was widely used, such as Industrial, medical care, aerospace and so on. It plays a key role in the national economy. Image filtering, image enhancement and image restoration are the important parts of image processing. This article introduces window function method, frequency sampling method and frequency exchange method to implement the design of 2D FIR digital filter based on MATLAB programming environment and gave example of simulation. The image enhancement is a important branch of the image processing, as well as the technical foundation of image edge extracting and image segmentation and so on. This paper also discussed the time domain processing frequency domain processing. During getting and transferring the image, image distortions influence the understanding of man and computer. The aim of image restoration is to recover the original uncorrupted images from noisy, blurred ones.
Key words: mage filtering; image enhancement; image restoration
