Image spatial filtering Q&A

• What is spatial domain and where is it?

The spatial domain is the image plane itself.

• What is spatial filtering?

Spatial filtering is similar with the point operations. Given a pixel at (x, y) in the input image, the output pixel of spatial filtering depends on not only the pixel at (x, y) but also the neighbourhood of the point (x, y).

• What are filter, mask, filter mask, kernel, template and window?

They are the same thing with different names. A spatial filter is matrix that defines a neighbourhood with predefined operation for spatial filtering.

• When filtering an image, should I use convolution or correlation?

To perform spatial filtering, both convolution and correlation can be used, as long as the intended operation is implemented through the mask. It is just a matter of preference.