Name of this window

I've started using a simple windowing function to low pass filter a 2D
image. Following the FFT, I multiply in the frequency domain with a
function that increases with distance from the origin (allowing for
wrapping). Then I IFFT back to the image domain. Basically the window
is this:

f = sqrt(alpha / (alpha + x^2 + y^2))

where x,y range from 1-n/2 to n/2 and alpha is a scalar.
Anyone know what this filter is called?

On 2004-12-23 01:47:28 +0100, spasmous@yahoo.com said:

> Anyone know what this filter is called?

A smoothing filter?
-- 
Stephan M. Bernsee
http://www.dspdimension.com

Stephan M. Bernsee wrote:
> On 2004-12-23 01:47:28 +0100, spasmous@yahoo.com said:
>
> > Anyone know what this filter is called?
>
> A smoothing filter?
Really? And what's it called when you're an idiot?

<spasmous@yahoo.com> wrote in message 
news:1103829541.581984.135040@f14g2000cwb.googlegroups.com...
> Stephan M. Bernsee wrote:
>> On 2004-12-23 01:47:28 +0100, spasmous@yahoo.com said:
>>
>> > Anyone know what this filter is called?
>>
>> A smoothing filter?
> Really? And what's it called when you're an idiot?
>

Well Spasmous,

The name of the filter is independent of Stephan's mental ranking. However 
he did describe its function correctly.

Do you expect someone to give you an answer when you are so quick to insult? 

spasmous@yahoo.com wrote:

> I've started using a simple windowing function to low pass filter a 2D
> image. Following the FFT, I multiply in the frequency domain with a
> function that increases with distance from the origin (allowing for
> wrapping). Then I IFFT back to the image domain. Basically the window
> is this:
> 
> f = sqrt(alpha / (alpha + x^2 + y^2))
> 
> where x,y range from 1-n/2 to n/2 and alpha is a scalar.
> Anyone know what this filter is called?
> 
If the "windowing" is done in the frequency domain it's called a filter, 
not a window.

Now who's the idiot?

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Tim Wescott wrote:

> If the "windowing" is done in the frequency domain it's called a
filter,
> not a window.
> 

Mm hm? Well that's great. Did you check my spelling too?

spasmous@yahoo.com > killfile
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

On 23 Dec 2004 12:38:14 -0800, spasmous@yahoo.com wrote:

>
>Tim Wescott wrote:
>
>> If the "windowing" is done in the frequency domain it's called a
>filter,
>> not a window.
>> 
>
>Mm hm? Well that's great. Did you check my spelling too?

What is it with the noobs and their questions here lately?   The
homework density seems to be going up and now we get a crop of
disrepectful twits that respond to help with insults.

Either that or the trolls are bored again.




Eric Jacobsen
Minister of Algorithms, Intel Corp.
My opinions may not be Intel's opinions.
http://www.ericjacobsen.org

Oh stop being a crybaby, I'm sure you've seen worse. But I'm intrigued
by what you call "help"... in other groups we actually use the
dictionary meaning.

Oh stop being a crybaby, I'm sure you've seen worse. But I'm intrigued
by what you call "help"... in other groups we actually use the
dictionary meaning.