Do you have any clues on this? I have the same problem.
I want to exclude some fixed regions in my picture stack because they contain an artifact that disturbs the classification.
I was thinking of the following approaches, but they don’t give the desired result. Maybe my post triggers some answers from you or the community:-)
I have freehand-drawn the regions that must be excluded and filled it with white (clear…invert…) before running the WEKA tool. In the classification settings I added a class “artifact”. I was hoping that the white color would force the classifier to assign the label “artifact” to all pixels in those regions, but it doesnt. The result is still dependant on the quality of the classification settings.
Also masking out those regions after running the tool is not a solution, because the labels outside the artifact regions are sometimes also labeled as artifact.
It would in fact be helpful if there would be a training feature that assigned a certain class name (“artifact”) in 100% of the cases to the white pixels and never to any other pixels.
One other way could be that the classification would only be done on the pixels inside a non rectangular region, without being affected by proximity to it’s border.
Does anyone have a clue?