[ITK-users] Inside value and outside value for itk::OtsuThresholdImageFilter

[沈庄明]

Hi all,


It seems to be a bug for itk.OtsuThresholdImageFilter. When I use SetInsideValue(0) and SetOutsideValue(255), I got the result displayed in Fig. 2, where inside voxel value is 255 and outside voxel value is 0. Inversely, when I use SetInsideValue(255) and SetOutsideValue(0), I got the result displayed in Fig. 3, where the inside voxel value is 0 and the outside voxel value is 255. It seems totally inversely. Is that right? Have someone else met this situation before? Thanks in advance.



Regards,


Zhuangming Shen



===============  My code  =================

import itk


reader = itk.ImageFileReader[itk.Image.SS3].New()

reader.SetFileName("ct.nrrd")

reader.Update()


otsu_filter = itk.OtsuThresholdImageFilter​[itk.Image.SS3, itk.Image.UC3].New()

otsu_filter.SetInput(reader.GetOutput())

otsu_filter.SetInsideValue(0)

otsu_filter.SetOutsideValue(255)

otsu_filter.Update()


writer = itk.ImageFileWriter[itk.Image.UC3].New()

writer.SetInput(otsu_filter.GetOutput())

writer.SetFileName("otsu.nrrd")

writer.Update()




Fig. 1    ct.nrrd

[cid:15b5cb2e-24ee-4092-99ff-d5bfd99c9d58]



Fig. 2  otsu segmentation result for SetInsideValue(0) and SetOutsideValue(255)

[cid:1c274aac-d532-4e55-8d5e-0a5847dea5af]



Fig. 3  otsu segmentation result for SetInsideValue(255) and SetOutsideValue(0)

[cid:917c3ca4-8e81-4d99-af7c-fc6af0639a43]


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/insight-users/attachments/20160408/2b774b6f/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pastedImage.png
Type: image/png
Size: 152425 bytes
Desc: pastedImage.png
URL: <http://public.kitware.com/pipermail/insight-users/attachments/20160408/2b774b6f/attachment-0003.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pastedImage.png
Type: image/png
Size: 21677 bytes
Desc: pastedImage.png
URL: <http://public.kitware.com/pipermail/insight-users/attachments/20160408/2b774b6f/attachment-0004.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pastedImage.png
Type: image/png
Size: 20783 bytes
Desc: pastedImage.png
URL: <http://public.kitware.com/pipermail/insight-users/attachments/20160408/2b774b6f/attachment-0005.png>