# Latest

**URL:** https://discourse.itk.org/latest.md?page=43

[Latest](https://discourse.itk.org/latest.md) · [Categories](https://discourse.itk.org/categories.md) · [Tags](https://discourse.itk.org/tags.md)

**Page:** 44

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## [Projecting 3D points onto the DRR image plane](https://discourse.itk.org/t/projecting-3d-points-onto-the-drr-image-plane/3430)

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**Author:** [@isuruwi](https://discourse.itk.org/u/isuruwi)\
**Replies:** 40\
**Last updated:** [December 8, 2021, 3:37pm UTC](https://discourse.itk.org/t/projecting-3d-points-onto-the-drr-image-plane/3430 "2021-12-08T15:37:43Z")

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I have created a volumetric mesh. I want to get the corresponding 2D projection coordinate (i.e. x, y positions) of each vertex coordinate on the DRR image projection plane. I went through the GetDRRSiddonJacobsRayTraci…

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## [LBFGS2 optimizer missing from python](https://discourse.itk.org/t/lbfgs2-optimizer-missing-from-python/4648)

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**Author:** [@matthew.andrew17](https://discourse.itk.org/u/matthew.andrew17)\
**Replies:** 1\
**Last updated:** [December 8, 2021, 3:36pm UTC](https://discourse.itk.org/t/lbfgs2-optimizer-missing-from-python/4648 "2021-12-08T15:36:05Z")

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The LBFGS2 optimizer seems to be missing from the python pip install - from the docs there should be a couple of classes (which are available in simpleITK) - LBFGS2Optimizerv4Enums and LBFGS2Optimizerv4Template. Only LBF…

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## [DRR image](https://discourse.itk.org/t/drr-image/4638)

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**Author:** [@wangjun456](https://discourse.itk.org/u/wangjun456)\
**Replies:** 6\
**Last updated:** [December 8, 2021, 3:18am UTC](https://discourse.itk.org/t/drr-image/4638 "2021-12-08T03:18:13Z")

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I use the example GetDRRSiddonJacobsRayTracing.cxx to generate DRR images. The data in the example can generate DRR images. when I used my own data, I can only generate an all black image. Does anyone know why?

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## [Image Registration: Learning rate for optimizer has no influence](https://discourse.itk.org/t/image-registration-learning-rate-for-optimizer-has-no-influence/4631)

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**Author:** [@sr1](https://discourse.itk.org/u/sr1)\
**Replies:** 6\
**Last updated:** [December 7, 2021, 3:41pm UTC](https://discourse.itk.org/t/image-registration-learning-rate-for-optimizer-has-no-influence/4631 "2021-12-07T15:41:01Z")

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Hi, I just followed the tutorial on 61\_Registration\_Introduction\_Continued and noted, that the convergence-speed does not change when I modify the learningRate of the optimizer I changed the value to learningRate=0 a…

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## [Sitk.ReadImage Supported Types](https://discourse.itk.org/t/sitk-readimage-supported-types/4645)

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**Author:** [@Furkan\_Gokhan](https://discourse.itk.org/u/Furkan_Gokhan)\
**Replies:** 1\
**Last updated:** [December 7, 2021, 2:21pm UTC](https://discourse.itk.org/t/sitk-readimage-supported-types/4645 "2021-12-07T14:21:49Z")

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Hello everyone, I am using SimpleITK library for reading MRA images. For example we are work on dcm and nii file and this can be work with Sitk.ReadImage but I dont know in the future that What file types can we encou…

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## [Is it possible to compute 2D Hessian value for each slice in a 3D medical array?](https://discourse.itk.org/t/is-it-possible-to-compute-2d-hessian-value-for-each-slice-in-a-3d-medical-array/4565)

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**Author:** [@Fivethousand](https://discourse.itk.org/u/Fivethousand)\
**Replies:** 2\
**Last updated:** [November 11, 2021, 2:12pm UTC](https://discourse.itk.org/t/is-it-possible-to-compute-2d-hessian-value-for-each-slice-in-a-3d-medical-array/4565 "2021-11-11T14:12:41Z")

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Hi, I am trying to compute 2-dimention hessian value for each slice in a 3D array. I succeed computing 3D hessian value for a 3D image or 2D hessian value for a single slice by using itk.MultiScaleHessianBasedMeasureIma…

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## [building as dll and include for c++](https://discourse.itk.org/t/building-as-dll-and-include-for-c/4608)

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**Author:** [@avispi](https://discourse.itk.org/u/avispi)\
**Replies:** 2\
**Last updated:** [December 5, 2021, 1:52pm UTC](https://discourse.itk.org/t/building-as-dll-and-include-for-c/4608 "2021-12-05T13:52:42Z")

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Hi. I want to try using ITK for some c++ development. I want to use it as any other external library I use (such as opencv i.e.) Preferably- dll + lib + include but also static libs + include is fine I’m compiling i…

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## [DRR](https://discourse.itk.org/t/drr/4637)

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**Author:** [@wangjun456](https://discourse.itk.org/u/wangjun456)\
**Replies:** 0\
**Last updated:** [December 4, 2021, 10:04am UTC](https://discourse.itk.org/t/drr/4637 "2021-12-04T10:04:51Z")

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I use the example GetDRRSiddonJacobsRayTracing.cxx to generate DRR images. The data in the example can generate DRR images. If I change my own data, I can only generate an all black image. Does anyone know why?

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## [2d-3d registration](https://discourse.itk.org/t/2d-3d-registration/4633)

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**Author:** [@wangjun456](https://discourse.itk.org/u/wangjun456)\
**Replies:** 2\
**Last updated:** [December 3, 2021, 1:39am UTC](https://discourse.itk.org/t/2d-3d-registration/4633 "2021-12-03T01:39:39Z")

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Do DSA images need to be converted into X-ray images when cta-dsa cerebrovascular 2D-3D registration?

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## [Pipeline confusion?](https://discourse.itk.org/t/pipeline-confusion/4594)

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**Author:** [@Theoretialperson](https://discourse.itk.org/u/Theoretialperson)\
**Replies:** 8\
**Last updated:** [December 1, 2021, 3:38pm UTC](https://discourse.itk.org/t/pipeline-confusion/4594 "2021-12-01T15:38:28Z")

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I’m having facing a problem that possibly stems for a misunderstanding of how pipelines work and get updated. I have the following piece of code, labelfile = labelfilelist\[0\] …

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## [How to establish type of study](https://discourse.itk.org/t/how-to-establish-type-of-study/4624)

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**Author:** [@Jakub\_Mitura](https://discourse.itk.org/u/Jakub_Mitura)\
**Replies:** 4\
**Last updated:** [December 1, 2021, 2:25pm UTC](https://discourse.itk.org/t/how-to-establish-type-of-study/4624 "2021-12-01T14:25:16Z")

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Hello is it possible given arbitrary dicom files to establish is it computer tomography, pet or MRI using simple itk python library Thanks for help !!

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## [GetDRRSiddonJacobsRayTracing returns empty image for certain angles](https://discourse.itk.org/t/getdrrsiddonjacobsraytracing-returns-empty-image-for-certain-angles/4626)

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**Author:** [@Steven](https://discourse.itk.org/u/Steven)\
**Replies:** 3\
**Last updated:** [December 1, 2021, 9:38am UTC](https://discourse.itk.org/t/getdrrsiddonjacobsraytracing-returns-empty-image-for-certain-angles/4626 "2021-12-01T09:38:24Z")

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I created a so-called “virtual C-arm” using the function GetDRRSiddonJacobsRayTracing Algirhtm \[1\], but for certain angles the resulting image is black. The following commands were used to generate the DRR’s. The angle …

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## [Orientation convention in dcm and nifti](https://discourse.itk.org/t/orientation-convention-in-dcm-and-nifti/4621)

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**Author:** [@BayesianMonk](https://discourse.itk.org/u/BayesianMonk)\
**Replies:** 3\
**Last updated:** [November 30, 2021, 3:00pm UTC](https://discourse.itk.org/t/orientation-convention-in-dcm-and-nifti/4621 "2021-11-30T15:00:41Z")

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Hi everyone, I am looking for the orientation convention in nifti and dicom. It is well known that in axial, nifti uses the RAS orientation, while dicom uses LPS orientation. But what about coronal and sagittal orient…

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## [Extending ITK DemonsRegistration Module to Use Custom Smoothing for Displacement Field](https://discourse.itk.org/t/extending-itk-demonsregistration-module-to-use-custom-smoothing-for-displacement-field/4622)

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**Author:** [@bbikdash](https://discourse.itk.org/u/bbikdash)\
**Replies:** 1\
**Last updated:** [November 29, 2021, 10:04pm UTC](https://discourse.itk.org/t/extending-itk-demonsregistration-module-to-use-custom-smoothing-for-displacement-field/4622 "2021-11-29T22:04:58Z")

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Hello, I’ve been working with the various Demons registration filters from SimpleITK as part of my graduate research in image registration. And I’ve been wondering if it possible to extend or change some of functionalit…

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## [AttributeError: module'itk' has no attribute'GradientDifferenceImageToImageMetric'](https://discourse.itk.org/t/attributeerror-moduleitk-has-no-attributegradientdifferenceimagetoimagemetric/4617)

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**Author:** [@seika](https://discourse.itk.org/u/seika)\
**Replies:** 2\
**Last updated:** [November 29, 2021, 5:49am UTC](https://discourse.itk.org/t/attributeerror-moduleitk-has-no-attributegradientdifferenceimagetoimagemetric/4617 "2021-11-29T05:49:13Z")

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When I use itk’s GradientDifferenceImageToImageMetric in a python environment, the above error occurred. Then I did not find the itkGradientDifferenceImageToImageMetricpython.py file in the packages directory. Why does…

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## [Warning with LBFGSB: does not support scaling](https://discourse.itk.org/t/warning-with-lbfgsb-does-not-support-scaling/4614)

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**Author:** [@reox](https://discourse.itk.org/u/reox)\
**Replies:** 2\
**Last updated:** [November 26, 2021, 1:52pm UTC](https://discourse.itk.org/t/warning-with-lbfgsb-does-not-support-scaling/4614 "2021-11-26T13:52:59Z")

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Here is a very simple example of an image registration: import SimpleITK as sitk x = sitk.Image(50, 50, sitk.sitkFloat32) x\[10:40,10:40\] = 1 y = sitk.Image(50, 50, sitk.sitkFloat32) y\[15:45,15:45\] = 1 sitk.ProcessObje…

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## [Multiply a vector image with scalar (SimpleITK)](https://discourse.itk.org/t/multiply-a-vector-image-with-scalar-simpleitk/4612)

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**Author:** [@Alsurayhi](https://discourse.itk.org/u/Alsurayhi)\
**Replies:** 2\
**Last updated:** [November 25, 2021, 6:19pm UTC](https://discourse.itk.org/t/multiply-a-vector-image-with-scalar-simpleitk/4612 "2021-11-25T18:19:57Z")

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To multiply a vector image with a scalar, I used import SimpleITK as sitk multiply = sitk.MultiplyImageFilter() multplied\_img = multiply.Execute(img , 0.5) my input image is of size 512 \*512 \*200 \*3. But it gives …

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## [Remove legacy in CI builds?](https://discourse.itk.org/t/remove-legacy-in-ci-builds/4609)

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**Author:** [@dzenanz](https://discourse.itk.org/u/dzenanz)\
**Replies:** 1\
**Last updated:** [November 24, 2021, 2:49pm UTC](https://discourse.itk.org/t/remove-legacy-in-ci-builds/4609 "2021-11-24T14:49:48Z")

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It has happened several times that ITK fails to build on one of the dashboard machines which has ITK\_LEGACY\_REMOVE=ON. This could be avoided if we had a CI build without legacy. Probably the best would be to add another …

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## [ITK implementation of geometric vector/tensor image transformations](https://discourse.itk.org/t/itk-implementation-of-geometric-vector-tensor-image-transformations/4596)

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**Author:** [@josempozo](https://discourse.itk.org/u/josempozo)\
**Replies:** 4\
**Last updated:** [November 23, 2021, 8:15am UTC](https://discourse.itk.org/t/itk-implementation-of-geometric-vector-tensor-image-transformations/4596 "2021-11-23T08:15:34Z")

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I am developing a new algorithm on itk and require the transformation of images which have different tensorial nature (vector, covector, symmetric rank-2 tensor). I was convinced that itk has this already implemented but…

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## [How does ConstantPadImageFilter work](https://discourse.itk.org/t/how-does-constantpadimagefilter-work/4592)

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**Author:** [@Theoretialperson](https://discourse.itk.org/u/Theoretialperson)\
**Replies:** 7\
**Last updated:** [November 19, 2021, 2:26pm UTC](https://discourse.itk.org/t/how-does-constantpadimagefilter-work/4592 "2021-11-19T14:26:14Z")

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Can someone help me understand how ITK’s ConstantPadImageFilter works? I was expecting to get an image with slightly different origin and the same spacing when padding: pad\_filter = itk.ConstantPadImageFilter\[ImageType,…

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## [Is it possible to apply a fraction of the transformation that obtained from the registration ?! (Elastix, and Transform)](https://discourse.itk.org/t/is-it-possible-to-apply-a-fraction-of-the-transformation-that-obtained-from-the-registration-elastix-and-transform/4591)

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**Author:** [@Alsurayhi](https://discourse.itk.org/u/Alsurayhi)\
**Replies:** 3\
**Last updated:** [November 18, 2021, 7:25pm UTC](https://discourse.itk.org/t/is-it-possible-to-apply-a-fraction-of-the-transformation-that-obtained-from-the-registration-elastix-and-transform/4591 "2021-11-18T19:25:05Z")

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I have lung CT data. I apply a deformable registration to align the inspiration scan to the expiration scan. I got the registered image and the transformationParamters. I used (transformix -def all) to get the deformati…

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## [Encountering undefined Behavior when writing DICOM images](https://discourse.itk.org/t/encountering-undefined-behavior-when-writing-dicom-images/4587)

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**Author:** [@Keyn34](https://discourse.itk.org/u/Keyn34)\
**Replies:** 4\
**Last updated:** [November 17, 2021, 3:26pm UTC](https://discourse.itk.org/t/encountering-undefined-behavior-when-writing-dicom-images/4587 "2021-11-17T15:26:05Z")

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Hello everyone, I am currently encountering undefined behavior when trying to write a DICOM series with headers taken from another series. I use only the gdcmIO and loop through all files to read the header with ReadIma…

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## [How to change the radius of the label (.tre file) in TubeTK](https://discourse.itk.org/t/how-to-change-the-radius-of-the-label-tre-file-in-tubetk/4590)

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**Author:** [@noteless](https://discourse.itk.org/u/noteless)\
**Replies:** 3\
**Last updated:** [November 17, 2021, 8:27pm UTC](https://discourse.itk.org/t/how-to-change-the-radius-of-the-label-tre-file-in-tubetk/4590 "2021-11-17T20:27:51Z")

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Using the TubeTK example: ‘Demo-ConvertTubesToImage.ipynb’ and the dataset of ‘100 Healthy Normal MRIs and MRAs from UNC’’ (https://data.kitware.com/#collection/591086ee8d777f16d01e0724/folder/58a372e38d777f0721a64dc6). …

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## [ITK Version and Python Version](https://discourse.itk.org/t/itk-version-and-python-version/4589)

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**Author:** [@imikejackson](https://discourse.itk.org/u/imikejackson)\
**Replies:** 4\
**Last updated:** [November 17, 2021, 6:31pm UTC](https://discourse.itk.org/t/itk-version-and-python-version/4589 "2021-11-17T18:31:36Z")

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We are trying to build a conda version of our application which needs ITK 5.2.1. The build goes off seemingly fine and I get the packages. Inspecting the packages indicates that ITK 5.2.1 is used/required for runtime. Bu…

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## [How to manipulate DICOM tags on individual slices from python code](https://discourse.itk.org/t/how-to-manipulate-dicom-tags-on-individual-slices-from-python-code/4481)

<div class="topic-metadata">

**Author:** [@br\_cpvc](https://discourse.itk.org/u/br_cpvc)\
**Replies:** 10\
**Last updated:** [November 17, 2021, 12:38pm UTC](https://discourse.itk.org/t/how-to-manipulate-dicom-tags-on-individual-slices-from-python-code/4481 "2021-11-17T12:38:07Z")

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I use the following code snippet for manipulating DICOM tags on individual slice: ... # insert tags per slice general\_metadata = gdcmIO.GetMetaDataDictionary() metadata\_array = \[\] for slice\_counter in r…

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## [How can I generate and save volume rendered images of brain arteries](https://discourse.itk.org/t/how-can-i-generate-and-save-volume-rendered-images-of-brain-arteries/4575)

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**Author:** [@Aleena\_Suhail](https://discourse.itk.org/u/Aleena_Suhail)\
**Replies:** 9\
**Last updated:** [November 16, 2021, 2:04pm UTC](https://discourse.itk.org/t/how-can-i-generate-and-save-volume-rendered-images-of-brain-arteries/4575 "2021-11-16T14:04:18Z")

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how can I generate and save images that are in nii (nifti) format into volume rendered image using simpleITK

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## [How to create spherical mask for all voxels of an organ](https://discourse.itk.org/t/how-to-create-spherical-mask-for-all-voxels-of-an-organ/4584)

<div class="topic-metadata">

**Author:** [@Jithendra\_Kumar\_V](https://discourse.itk.org/u/Jithendra_Kumar_V)\
**Replies:** 1\
**Last updated:** [November 15, 2021, 10:37pm UTC](https://discourse.itk.org/t/how-to-create-spherical-mask-for-all-voxels-of-an-organ/4584 "2021-11-15T22:37:49Z")

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Hi, I am trying to iterate all the voxels of an organ. For each voxel, need to create a 30 mm spherical mask and get the corresponding standard deviation. Finally pick the voxels with least standard deviation. Please gu…

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## [Is there a format for label information (names, color, etc.)](https://discourse.itk.org/t/is-there-a-format-for-label-information-names-color-etc/4579)

<div class="topic-metadata">

**Author:** [@dyoll](https://discourse.itk.org/u/dyoll)\
**Replies:** 2\
**Last updated:** [November 14, 2021, 10:43pm UTC](https://discourse.itk.org/t/is-there-a-format-for-label-information-names-color-etc/4579 "2021-11-14T22:43:04Z")

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Hi there Is there any convention for storing label information (tissue name, color, index, maybe other metadata) in medical image segmentation? Does ITK support loading/saving this metadata? How does the ML community h…

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## [ITK Registrationv4 and PDEDeformableRegistration](https://discourse.itk.org/t/itk-registrationv4-and-pdedeformableregistration/4535)

<div class="topic-metadata">

**Author:** [@Anurag\_Ranjak](https://discourse.itk.org/u/Anurag_Ranjak)\
**Replies:** 4\
**Last updated:** [November 12, 2021, 3:08pm UTC](https://discourse.itk.org/t/itk-registrationv4-and-pdedeformableregistration/4535 "2021-11-12T15:08:57Z")

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Is it possible to use itk registration v4 algorithms such as SyN or Time Varying Velocity Field transforms in the ITKPython package. I installed the itk package and am doing something like this primary\_image\_path = "fix…

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## [itk-js: Create Image from Buffer](https://discourse.itk.org/t/itk-js-create-image-from-buffer/2847)

<div class="topic-metadata">

**Author:** [@Athius](https://discourse.itk.org/u/Athius)\
**Replies:** 5\
**Last updated:** [November 12, 2021, 3:05pm UTC](https://discourse.itk.org/t/itk-js-create-image-from-buffer/2847 "2021-11-12T15:05:44Z")

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Hi everyone, I have some application that transfert a json file that contains buffer of pixels, image dimension, spacing, origin and type of each pixels (int, unsigned int, etc…). I can’t use a standard format like nrrd…

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