[scilab-Users] 3D plot of Butterworth polynomial?

[Ronald Michaels]

Hi - 

Assuming that you want a circular filter:

Take the first equation in your link below and set a and b to 1.  Then
set the origin of the x,y axis system to the center of your image, i.e.
x = 0 and y = 0 at center of image.  Calculate r for each x,y pixel
location.  Then use r in the second equation in link to find the value
of the filter for that x,y location.  Find the equivalent position in
image coordinates (u,v) and place filter value there in Filter array.

Ron


On Sat, 2010-11-06 at 09:26 +0330, hadi motamedi wrote:
> Dear All
> Can you please let me know how to obtain a 3D plot of the Butterworth
> polynomial?
> Thank you
> For the 2-D Butterworth polynomial , please see
> :http://www.clear.rice.edu/elec301/Projects01/image_filt/filter.html
>