Sorry for the long chain of questions, but I am struggling really hard with VTK ( I wrote a whole framework for these stuff in my previous job, but here I need to use VTK and I am probably struggling mostly because the line of thought behind VTK is very different from what I had in my own framework).
When I use the OutputSpacing outputOrigin adn OutputExtension I do get respositioning and sclaing effects, but they do not make sense for me.
I have an image that is 512x512. When I try to use the Origin and extension as 256 what I get is not half of the image as displacement, it is a bit over 3/4 of the image.
I tried to check the values these attributes have before I try to set them, with the GetMethods just after I have set the InputPort as the output of a vtk Image. … but the values are always zero. I am having a really hard time to understand what the parameters of the methods are supposed to be (and if they are in pixels or mm ) since they are named a,b,c,d,e … etc…
If I have an image of 512x512 and I want to get the upper right quadrant of the image, scaled up to 512x512. What should these parameters be? (On my own framework I would just pass a corner and 2 direction vectors in pixel space, and a parameter image where to render to (The zoom woudl be implicit from the image size)… maybe I am getting confused because of some fundamental difference in the way of thinking.