Image restoration is the process of restoring the degraded or corrupted image back to its original form. It is the initial step of image processing. Noise is added in the image while sending an image from one place to another via satellites, wireless, or during image acquisition process. There are various types of noises such as salt and pepper noise(impulse noise), Gaussian noise etc. The main goal of image restoration is to recover or improve the quality of an image, identifies the type of noise and attempts to reverse it. The restoration process improves the image by using a priori knowledge of the degradation process. The degradation process first identifies the type of noise, and then apply the inverse process to recover the corrupted image. In this paper various spatial domain filters are discussed which are used to remove noise from the images.