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<P><FONT SIZE=2>Hi all,<BR>
<BR>
Sorry for a subject title so complicated, I tried to find an "explicit" sentence...<BR>
<BR>
In order to illustrate my questions, let's take a simple example:<BR>
<BR>
filter A will perform this operation in its GenerateData() :<BR>
<BR>
Given a set of pixels within the requested region of an input image I, do<BR>
{<BR>
// current Pixel in the input is named input_px. The corresponding pixel at the same position in the output is called ouput_px <BR>
apply a filter B locally: "output_px = B( input_px)"<BR>
}<BR>
<BR>
Some remarks:<BR>
<BR>
a) B should be created _before_ the traversal of the pixels set.<BR>
b) B performs a _local_ treatment, that means it just needs a required region on the input (as usually performed in itk with the region enlargement techniques.)<BR>
c) B is a filter, _not_ an imageFunction, that means that no current itk class allows to do:<BR>
<BR>
B->SetInputImage(I);<BR>
output_px = B->Evaluate( input_px_position );<BR>
<BR>
The questions are then:<BR>
1) How to deal with remark c)? Should I:<BR>
- create a requested region whose size is (1,1,1) in 3D and whose position is the current input pixel<BR>
- set it to filter B<BR>
- Update() on B<BR>
- Retrieve the value of output_pixel with GetPixel()<BR>
<BR>
2) If my previous solution is correct, how the filter B will behave with successive SetRequestedRegion + Update() calls as we have to traverse a set of different pixels that are not continuous? As the size of the requestedRegion doesn't change, its internal buffered region will remains the same ( i.e requested region + elargement needed for processing)? Or due to call of GetPixel of different regions within the image, some allocation will be done?<BR>
<BR>
I do not need to perform a kind of "GraftOutput() operation" as everytime I can copy the value of the output_pixel in another structure that is much leighter than the whole image as it is not very dense.<BR>
<BR>
I hope I have been enough clear...!<BR>
<BR>
Thank you!<BR>
<BR>
Jerome<BR>
<BR>
<BR>
-----------------------------------<BR>
Jerome SCHMID<BR>
Project Manager/ Engineer<BR>
Augmented and Virtual Reality<BR>
MIS Centre<BR>
Prince of Wales Hospital<BR>
Chinese University Of Hong-Kong<BR>
-----------------------------------<BR>
<BR>
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