Given the magnitudes of the displacements, Dartel would probably do a
better job with these images. However, if you want to try to achieve
much greater deformations with HDW, then you could try reducing the
amount of regularisation and increasing the number of iterations.
Best regards,
-John
On 21 October 2010 16:35, Greg Book <[log in to unmask]> wrote:
> I've been using HDW for a little while and been able to do most of what I
> want, however I'm not able to get the warps quite the way I need them.
> I have some CT data that I cropped to expose the structures of interest.
> These images are 80x80x80 mm. (1 voxel = 1 mm). Differences between
> structures in the images are on the order of 5mm, so I was hoping that the
> images would be warped internally by 5 voxels. However, after warping,
> voxels in the warped image are only displaced by about 1mm... so in the end
> the structures don't match up between two warped images and are still 4mm
> apart from where they should be.
>
> I'm attempting to warp the aorta, so I'm basically trying to warp a 20mm
> diameter tube to a 25mm diameter tube. Is this something that HDW can do?
> I'm wondering how strong the warping is, and how I can adjust it? Should I
> leave the CT images at 256x256x140.
>
> The 2D circle to square warping in Chapter 4 of the human brain function
> book is exactly the kind of warping effect I'm looking for.
>
|