Filtering is a general notion of transforming the image intensities in some way so as to enhance or deemphasize certain features
Image Spatial Filtering
Filtering in the Domain of Image Space (Spatial Domain)
The mask is placed over the source image, mask elements are multiplied by pixel values, and the results added to form an output pixel.
•The convolution kernel is normally referred to as the ‘filter’, since it dictates what elements of the input image are allowed to pass through to the output image.
•By choosing an appropriate filter, we can enhance certain aspects of the output and attenuate others.