comp.lang.idl-pvwave archive: archive » Convol with Kernel Dependency Of the Radius to the Middle

Home » Public Forums » archive » Convol with Kernel Dependency Of the Radius to the Middle

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: Convol with Kernel Dependency Of the Radius to the Middle [message #27770 is a reply to message #27639]

Wed, 31 October 2001 01:14

bente
Messages: 13
Registered: October 2001

Junior Member

Hi,
> I assume you mean that the function that describes the 3d kernel depends on
> the radial (cartesian) distance of the image voxel from a point in the
> image:
> *pseudo formula alert!*
> Image'(x,y,z) = Image [convolved_with] Kernel(R(x,y,z))
> where R(x,y,z) = sqrt((X-Xo)^2+(Y-Yo)^2 + (Z-Zo)^2))

Thats right.

> If so, I guess the question is, what is the dependency of the kernel on R?
> If linear then maybe the radial aspect of the kernel is separable

My Proffessor had the "nice" idea, that a PET image, has a better
resolution in the middle of the picture than on the edge for each
slice. To simulate this he wants that the Kernel has a dependency of x
& y (not z!) in that form that the FWHM (Full Width Half Max) of a 3D
Gaussian Kernel increases linear with the distance from the middle.

Thats a bit too much for my "weak" knowledge of IDL, I solved it in
that form, that i convol the whole stuff 10 times and then copy
several "barrels" together to the whole picture. It looks ok, but itï¿½s
not as smooth as it should be.

I think I have to write a complete new convol function :-((
smile

thanks for the answer.

Kay

Report message to a moderator

[Message index]

		Convol with Kernel Dependency Of the Radius to the Middle By: bente on Tue, 23 October 2001 07:18
		Re: Convol with Kernel Dependency Of the Radius to the Middle By: Martin Downing on Tue, 30 October 2001 05:40
		Re: Convol with Kernel Dependency Of the Radius to the Middle By: bente on Wed, 31 October 2001 01:14
		Re: Convol with Kernel Dependency Of the Radius to the Middle By: bente on Fri, 02 November 2001 00:31
		Re: Convol with Kernel Dependency Of the Radius to the Middle By: Martin Downing on Wed, 31 October 2001 07:09

Previous Topic:	Re: gif license
Next Topic:	IDL Pricing

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 17:31:59 PDT 2025

Total time taken to generate the page: 0.00589 seconds