Robert,

Thank you so much for this FFT example. Now I have questions. Where in the
program can we change parameters to do filtering such as getting rid of
high frequency (noise) or low frequency (background) variations in pixel
intensity ?
Do we need to have a square image or only have width and height to be
multiples of 2 ?

Thanks again.

Cheers

Patrick




>>From the nimble fingers of Robert Covington (artlythere@...)
>>(20/12/2001 9:51 AM) came...
>>
>>>> Was I mistaken in thinking that a saved FFT'd image could be re-opened and
>>>> de-FFT'd?
>>>
>>> Yep. :)
>>>
>>> It is just an image maker, not a storage medium.
>>>
>>If - as we now know - it is possible to FFT an image, why does the converse
>>not work. Is the raw material for your de-FFTer something other than the
>>image shown? If so, my unflinching trust in you has taken a nasty hit.
>>--
>>Ted Spencer; ted@...
>
>Yes, the raw material for the reverse transform) is not even the image you
>see. It is the array derived from the forward transform. That is why doing
>a reverse does nothing if the forward hasn't been done yet.
>
>The reason you don't get the same image back out from some transformed
>randomly re-loaded by Files$ image is that you don't have the reals and
>complex numbers used to create it. The image you see is just a metaphor for
>the array in memory, not the actual goods.
>
>
>You can still trust me. It has been a rough week. Don't bum me out.
>
>Robert