[vtkusers] vtkImageReslice and SetSlabNumberOfSlices(int)

[David Gobbi]

Yes, the slab is centered wrt the reslice plane.  So if SlabNumberOfSlices
is even, then the two middle "slab" slices will be on either side of the
reslice plane (+0.5 above and -0.5 below).

Though this isn't quite related, note that it is possible to change the
spacing between the "slab" slices with SetSlabSliceSpacingFraction().

 - David

On Fri, Jul 3, 2015 at 3:51 AM, Marco Sambin <m.sambin at gmail.com> wrote:

> Hi all,
>
> with reference to this old question of mine (see below), I would like a
> clarification:
>
> suppose that the output z-spacing is set to 1 mm on my vtkImageReslice
> instance. Also, suppose that I call SetSlabNumberOfSlices(2) on my reslicer.
> Where will the 2 slices used to compute the slab image be located w.r.t.
> the position of my reslice plane? Will the first slice be 0.5 mm "above"
> and the second slice be 0.5 mm "below" my reslice plane? In other words,
> will the slices always be "centered" w.r.t. the position of my reslice
> plane?
>
> Maybe this is a silly question, but I like to exactly understand this
> point.
>
> Thanks in advance for the clarification.
> Regards,
>
> Marco
>
>
> On Mon, Mar 25, 2013 at 9:59 PM, Marco Sambin <m.sambin at gmail.com> wrote:
>
>> Hi David,
>>
>> Thanks for the clarification.
>> I will test this soon.
>> Regards,
>>
>> Marco
>>  Il giorno 25/mar/2013 14:24, "David Gobbi" <david.gobbi at gmail.com> ha
>> scritto:
>>
>>> Hi Marco,
>>>
>>> The way it works is this: vtkImageReslice is creating the slab by
>>> extracting N samples and combining them, where the distance between
>>> the samples is set by the third argument to SetOutputSpacing().  If
>>> the SlabNumberOfSlices is N, then the slab thickness is
>>> (N-1)*spacing[2] where spacing[2] is the z-spacing set with
>>> SetOutputSpacing(spacing[0],spacing[1],spacing[2]).
>>>
>>> Summary: thickness = (N - 1)*spacing[2]
>>>
>>> Slab mode is equivalent to extracting N slices and combining them.
>>>
>>>  - David
>>>
>>> On Mon, Mar 25, 2013 at 6:01 AM, Marco Sambin <m.sambin at gmail.com>
>>> wrote:
>>> > Hi all.
>>> > I am looking at implementing thick reformats through vtkImageReslice.
>>> >
>>> > Even after looking at the documentation, I did not fully understand the
>>> > SetSlabNumberOfSlices(int) method. For instance, in cases of an oblique
>>> > reformat, what is considered to be a "slice"? What defines the
>>> "thickness"
>>> > of a single slice, thus determining the total slab thickness resulting
>>> from
>>> > calling SetSlabNumberOfSlices(X)?
>>> >
>>> > I was expecting a call like SetSlabThickness(...), rather than
>>> > SetSlabNumberOfSlices(...).
>>> >
>>> > I would appreciate any comment on this.
>>> > Thanks in advance.
>>> >
>>> > Marco
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20150703/b8ad9728/attachment.html>