how to get a sinc profile out of a pic?

Hi,I want to improfile an image and to get something like that:

the image that im working with is:

and when I improfile it,all I get is that:

I want to make it look like a sinc function(top image),any ideas?

Answer 1

[Image Analyst]

Why do you think the profile should look like that when you took the actual profile and it clearly does not look like that? If you want to modulate the actual profiles by multipying by a big wide sinc, you certainly can to that. What do you actually want to do:

1. find the actual profile that's actually there, or
2. modify the actual profile to make it look like what you want, or
3. synthesize a perfect sinc envelope of a higher frequency signal, ignoring the image altogether?

Answer 2

[Star Strider]

Are you looking for autocorrelation? If so, use xcorr.

[Sagi]

doesn't work,out of memory...

[Star Strider]

I don’t have your data, so I suggest using the ‘maxlags’ option. Looking at the x-axis of your top figure, perhaps 500 for ‘maxlags’ would work.