fspecial (disk)

Hello everyone,

I have employed fspecial several times for the exercises of image processing course (h=special('disk',5);). But I have no idea how disk filter function works. Maybe sounds silly but I really appreciate if someone at least explains the big picture behind it.

Thanks in advance for your responses!

Answer 1

[Jan]

We can assume, that you have read the documentation already:

doc fspecial

The term "Circular averaging filter (pillbox)" sounds very descritpive: The average over a circular shape is calculated. What exactly is not clear about this?

[Shohreh Kr]

Thanks! but how circular averaging works on an image?

[Jan]

The value of each pixel is replaced by the mean of the values of all pixels inside a circle around this pixel.

What do you want to know exactly? How the circular mask is applied? How averaging RGB values work? If this is performed by 2 loops or vectorized? What the opical effect is?