Slice display - why image in slicer is more smoothing

Support
1

Hello! It is not a bug. I just wonder something about the slice display in Slicer. when I used vtk6.2 to display image with vtkImageReslice::SetInterpolationModeToLinear() and vtkImageActor:InterpolateOn(), I got Figure A which was not smoothing. But I load the same image in Slicer, then I got Figure B which was very smoothing. I tried to set output spacing of vtkImageReslice as 0.25 x original spacing, and then I got the result as slicer’s. However, I found it became slower when I paged down, and there was no this problem in slicer.

Can you tell me the additional operations has done by Slicer? Thank you very much!

Figure A
image
Figure B

image
image805×397 31.6 KB

2

Answer from @pieper:

Maybe the difference is that Slicer uses vtkImageReslice to resample the images to screen space (pixels on your monitor) but when you use a vtkImageActor it uses the original image as a texture.

3

Thank you for answering my question. Does Slicer use ImageActor to display image or use other actor?

4

vtkImageActor is good for simple use cases but we need many more features in 3D Slicer. Therefore, we prepare all data using VTK filter pipelines and render it by a simple actor and polydata mapper, displaying texture on a rectangle.

5

Thank you very much! This is very useful for me. I wil try it.