vtkImageReslice: how to make point in the center of output image

I am using vtkImageReslice to generate an image by resliceAxes which is created by a normal direction and passing a point . In the output image, I can define its size by SetOutputExtent.

my question is how to make the point always in the middle of output image.

Thank you!

It is still not solved. Appreciate if anyone can help.

Thank you!

Please try for yourself first and then share your code and screenshots.