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<div class="moz-cite-prefix">Hi Mengda,<br>
<br>
yes, doing the computation yourself is faster. An example was
given here:
<a class="moz-txt-link-freetext" href="http://vtk.1045678.n5.nabble.com/Fast-element-access-of-vtkImageData-td4640137.html#a4640179">http://vtk.1045678.n5.nabble.com/Fast-element-access-of-vtkImageData-td4640137.html#a4640179</a><br>
<br>
As also was pointed out in this thread another option are image
iterators. However, I don't know if they are as fast as direct
access.<br>
<br>
Regards,<br>
Dominique<br>
<br>
Am 20.11.2013 05:30, schrieb Mengda Wu:<br>
</div>
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cite="mid:CALmcJSDj-S7UN3AOZ3Y-nmHet46DXLeD5HOY3dwXVSS4v8+g1A@mail.gmail.com"
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<div>Hi all,<br>
<br>
</div>
I am trying to use vtkImageData::GetScalarPointer
inside the loop through all the voxels in a huge 3D image
(512x512x300). But it seems this function is pretty slow.
A code sample is like this:<br>
<br>
int* dims = aImage->GetDimensions();<br>
int dim[3];<br>
for(dim[2] = 0; dim[2] < dims[2]; dim[2]++)<br>
{<br>
for(dim[1] = 0; dim[1] < dims[1]; dim[1]++)<br>
{<br>
for(dim[0] = 0; dim[0] < dims[0]; dim[0]++)<br>
{<br>
double* curr =
static_cast<double*>(aImage->GetScalarPointer(dim));<br>
*currhist = 1.0;<br>
}<br>
}<br>
}<br>
}<br>
<br>
</div>
I mean should I just get the pointer of the first vosel
and compute the poitner addresses for the rest of voxels
myself? Should it be faster? Does vtkImageData store all
voxels continuously? What about if I have multiple
components per voxel?<br>
<br>
</div>
Thanks,<br>
</div>
Mengda<br>
<div>
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<div> <br>
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