I have an audio background so a lot of my thinking about image processing is translated into audio terms in my head.
There are two main differences between images and audio (besides the 1D/2D thing).:
-
Images have all positive values and audio has negative and positive values. Audio has rapid fluctuations from positive to negative, which is quite different to image data which, even if it fluctuates, tends to be smoother.
-
Audio processing generally is one sample at a time, with no knowledge of future samples. Images have all the pixels available to you at once.
IIRC A simple low pass filter in audio is:
(current sample x F) + (previous sample x (1-F) )
A high pass filter is:
(current sample x F) - (previous sample x (1-F) )
where F determines the cut-off frequency