I have to develop a small image application - reading in a sequence of images(volume) and doing some simple interactive image processing on each of them to identify some features. The breadth of classes in VTK is vast and not sure what subset of classes would be the easiest to start with. I would want to be able to mouse and key input to locate pixel (position and possibly pixel value) to start some image processing algorithms (which I can do in the background and able to display. It would be nice to be able to show the results in a separate window as well. Any suggestions (list of classes to consider, for instance, or examples – I did look at a bunch of them, but couldnt quite narrow down based on my needs).
It may seem like a small application, but implementing this, especially the interaction part in views in a user-friendly way is hard. I would not recommend to start from scratch but instead customize existing VTK-based applications, such as ParaView or 3D Slicer (in fact, probably you don’t even need to customize these applications, just run your Python script in these applications that takes user inputs and starts the custom processing).
If you think building on existing applications would be an overkill and you will never need anything more than taking a few input points from an image then you might consider using vtk.js, as users nowadays expect to do such simple things in their web browser and reluctant to install applications.