<div dir="ltr"><div class="gmail_extra">Dear all responders,<br><br>Many thanks for the warm replies.<br>I learned a lot from your ideas.<br><br>Robert, your implementation is very helpful and really answered my needs because less iterators increments are needed :-)<br>
<br>eventually, I managed with the implementation but just wanted to notify that with the following code due to most of your suggestions:<br><br> for (it = list.begin(); it <
list.end(); it++)<br>
{<br>
output_val =(*it)->Get() + output_val; //get values from each image and
insert in the output
image<br> ++(*it);<br>
}<br><br> I encountered with a run time error:<br><br>Unhandled exception ...: Access violation reading location ...<br> const IndexType &bufferedRegionIndex = this->GetBufferedRegion().GetIndex();<br> ImageHelper<VImageDimension,VImageDimension>::ComputeIndex(bufferedRegionIndex, offset, m_OffsetTable, index);<br>
<br>after debugging it has turned out that this RT error occurred before the end of the image line. <br>(for example: my x dimension is x1=a and that RT occurs at x1=a-1).<br><br>What have I missed?<br><br>Best,<br>Hila<br>
<br> <br><br><div class="gmail_quote">On Mon, Apr 23, 2012 at 6:13 PM, robert tamburo <span dir="ltr"><<a href="mailto:robert.tamburo@gmail.com" target="_blank">robert.tamburo@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="gmail_extra">Assuming the images have corresponding pixels by the same index, another approach is to use an iterator to parse the output image, then get the value of the pixel for each image in a list and compute the output value. Non-compilable code:<br>
<br>// Iterate over the output image with ImageRegionIteratorWithIndex (e.g., output_it)<br>
for(output_it.GoToBegin(); !output_it.IsAtEnd();
++output_it)<br>
{<br> // Get the index during image iteration<br> index = it.GetIndex();<br> // Iterate over a list of images<br> for(unsigned int i = 0 ; i < imageList.size(); i++)<br> {<br> output_val += imageList[i]->GetPixel(index);<br>
}<br> // Set pixel in output image to output_val.<br> output_image->SetPixel(index);<br><br> // Reset output_val<br> output_val = 0;<br> }<br>
<br>----> That being said, take a look at itkNaryAddImageFilter. I think that does what you want.<div><div class="h5"><br><br><br><div class="gmail_quote">On Mon, Apr 23, 2012 at 10:40 AM, Hila Hiler <span dir="ltr"><<a href="mailto:hilahiler@gmail.com" target="_blank">hilahiler@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div>Thank you for your interest.<br><br>I'll try to explain it as clear as I can...<br>The major goal is to generate an image which any of its pixel is the sum of other images corresponding pixels. <br>
For example: any pixel of the new image should be the sum of the corresponding pixels from the other images (im1(pix) = im2(pix)+im3(pix)). <br>Note that because I don't know in advance the number of the input images, I created a STL container to store the iterators of the images. I chose this way in because later I can increment all the iterators in one loop (until the end of the container) ...<br>
<br>So, back to my code:<br><br>vector of iterators:<br>| it_1 | it_2 | ... | it_n |<br><br>// iterators for the n input images <br>constIteratorType it_1 (img_1, img_1->GetRequestedRegion()); <br>constIteratorType it_2 (img_2, img_2->GetRequestedRegion()); <br>
...<br>constIteratorType it_n (img_n, img_n->GetRequestedRegion()); <br><br>//iterator of the output image<br>
iteratorType
output_it (output_img, output_img->
GetRequestedRegion());<br><br>//container to store the iterators<br>
std::list<constIteratorType> list;<br>std::list<constIteratorType>::iterator it;<br><br>// iterator of the list that suppose to initialize all of the iterators (it_1, it_2, etc)<br></div> for(it =
list.begin(); it < list.end(); it++)<br>
{<br>
it->GoToBegin();<br> }<br><br>//move in parallel with all of the input images and set in the output image the sum of the corresponding images pixel<br>
for(output_it.GoToBegin(); !output_it.IsAtEnd();
++output_it)<br>
{<br> output_val = 0;<br> for (it = list.begin(); it <
list.end(); it++) //move on each image in the list and get it's pixel value <br>
{<br>
output_val = it->Get() + output_val; //get values from each image and
insert in the output
image<br> //
How do I forward the image's iterator from here
?????<br>
}<br>
output_it.Set(output_val);<br> }<br><br>Hope that now it's clearer ...<br><br>Hila<br><br><br><br><div class="gmail_quote">On Mon, Apr 23, 2012 at 4:51 PM, alex Dowson <span dir="ltr"><<a href="mailto:alexdowson@hotmail.com" target="_blank">alexdowson@hotmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div dir="ltr">
<div style="font-size:12pt;font-family:'Calibri'">
<div>Hi</div>
<div> </div>
<div>I think I still did not understand your problem completely . Why you
want to store image in container ? Can you describe what exactly you
trying to do ?</div>
<div> </div>
<div> </div>
<div>Alex</div>
<div> </div>
<div style="font-size:small;font-style:normal;text-decoration:none;font-family:'Calibri';display:inline;font-weight:normal">
<div style="FONT:10pt tahoma">
<div> </div>
<div style="BACKGROUND:#f5f5f5">
<div><b>From:</b> <a title="hilahiler@gmail.com" href="mailto:hilahiler@gmail.com" target="_blank">Hila Hiler</a> </div>
<div><b>Sent:</b> Monday, April 23, 2012 7:15 PM</div>
<div><b>To:</b> <a title="alexdowson@hotmail.com" href="mailto:alexdowson@hotmail.com" target="_blank">alex Dowson</a> </div>
<div><b>Cc:</b> <a title="insight-users@itk.org" href="mailto:insight-users@itk.org" target="_blank">insight-users@itk.org</a> </div>
<div><b>Subject:</b> Re: [Insight-users] container for iterators of
images</div></div></div>
<div> </div></div><div><div>
<div style="font-size:small;font-style:normal;text-decoration:none;font-family:'Calibri';display:inline;font-weight:normal">
<div dir="ltr">
<div class="gmail_extra">Hi Alex,<br>first of all, many thanks for the
response.<br><br>I'm afraid that you haven't noticed that I did the same as
described in your link (it was the easy part) ...<br>Actually my question was
about a vector of iterators to itk images.<br>Please, read my attached code.
I'll be pleased to understand what have I
missed.<br><br>Regards,<br>Hila<br><br><br>
<div class="gmail_quote">On Mon, Apr 23, 2012 at 4:08 PM, alex Dowson <span dir="ltr"><<a href="mailto:alexdowson@hotmail.com" target="_blank">alexdowson@hotmail.com</a>></span> wrote:<br>
<blockquote style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex" class="gmail_quote">
<div dir="ltr">
<div dir="ltr">
<div style="FONT-FAMILY:'Calibri';FONT-SIZE:12pt">
<div>Hi</div>
<div> </div>
<div>Look at this examples</div>
<div> </div>
<div> </div>
<div><a href="http://www.itk.org/Wiki/ITK/Examples/Iterators/ImageRegionConstIterator" target="_blank"><font face="Times New Roman">http://www.itk.org/Wiki/ITK/Examples/Iterators/ImageRegionConstIterator</font></a><font face="Times New Roman"> </font></div>
<div><a href="http://www.itk.org/Wiki/ITK/Examples/Iterators/ImageRegionIterator" target="_blank"><font face="Times New Roman">http://www.itk.org/Wiki/ITK/Examples/Iterators/ImageRegionIterator</font></a><font face="Times New Roman"> </font></div>
<div> </div>
<div> </div>
<div> </div>
<div> </div>
<div> </div>
<div> </div>
<div style="FONT-STYLE:normal;DISPLAY:inline;FONT-FAMILY:'Calibri';FONT-SIZE:small;FONT-WEIGHT:normal;TEXT-DECORATION:none">
<div style="FONT:10pt tahoma">
<div> </div>
<div style="BACKGROUND:#f5f5f5">
<div><b>From:</b> <a title="hilahiler@gmail.com" href="mailto:hilahiler@gmail.com" target="_blank">Hila Hiler</a> </div>
<div><b>Sent:</b> Monday, April 23, 2012 5:57 PM</div>
<div><b>To:</b> <a title="insight-users@itk.org" href="mailto:insight-users@itk.org" target="_blank">insight-users@itk.org</a>
</div>
<div><b>Subject:</b> [Insight-users] container for iterators of
images</div></div></div>
<div> </div></div>
<div style="FONT-STYLE:normal;DISPLAY:inline;FONT-FAMILY:'Calibri';FONT-SIZE:small;FONT-WEIGHT:normal;TEXT-DECORATION:none">
<div>
<div>
<div dir="ltr">Hi All,<br><br>I'd like to generate a new image by summarizing
some other images in the same dimensions.<br>So I generated a new image and a
std::list for the images iterators. (actually, I thought that this dynamic
container is the best way to mange an unknown number of images)<br><br>For
now, it isn't working because I don't know how to forward the image's iterator
from that vector. in other words, how do I do the same as: output_it++ from a
vector?<br><br>Here is my code:<br><br> typedef
itk::ImageRegionIterator
<ImageType>
iteratorType;<br> typedef
itk::ImageRegionConstIterator
<ImageType>
constIteratorType;<br><br>
constIteratorType first_it (first_img,
first_img->GetRequestedRegion()); <br>
iteratorType
output_it (output_img, output_img->
GetRequestedRegion());<br><br>
std::list<constIteratorType> list;<br>
std::list<constIteratorType>::iterator it;<br><br>
list.push_back(first_it);<br><br> if
(second_img.IsNotNull())<br>
{<br> constIteratorType second_it
(second_img, second_img->GetRequestedRegion());
<br> list.push_back
(second_it);<br> }<br><br> //initialize
all the iterators at the begin of input images<br> for(it =
list.begin(); it < list.end(); it++)<br>
{<br>
it->GoToBegin();<br> }<br><br>
for(output_it.GoToBegin(); !output_it.IsAtEnd();
++output_it)<br>
{<br> for(it = list.begin(); it <
list.end(); it++)//move on the images and get at each iteration the pixel
value and insert to the new
image<br>
{<br>
output_val = it->Get() + output_val; //get values from each image and
insert in the output
image<br> //
How do I forward the image's iterator from here
?????<br>
}<br>
<br>
output_it.Set(output_val);<br><br> }<br><br><br><br>Any
thoughts would be very welcome ...<br>Hila<br></div></div></div>
<hr>
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<br></blockquote></div><br><br clear="all"><br></div></div><span class="HOEnZb"><font color="#888888">-- <br>robert<br><br>
</font></span></div>
</blockquote></div><br></div></div>