ABSTRACT
The image can be thought of as a matrix of pixels, each pixel carrying three numerical values. The pixel position identifies a spatial coordinate and each pixel value represents the intensity of the colour channel at that position. The three values of a pixel depend on the colour model employed. For example, they may represent primary colour components of red, green and blue, or they may represent luminance and two normalized chromaticity values. Applying digital image-processing techniques in this manner to the image data as termed working in the spatial domain' or 'spatial image processing'. Frequency space filters are often developed from a consideration of the frequency content of the image and the required modification to that frequency content, rather than an alternative route to a real space convolution operation. The process of recovering an image that has been degraded, using some knowledge of the degradation phenomenon, is known as image restoration.
