Delete backgroung and manual 3D volume rendering

[PedroFernandez]

To whom it may concern,

I am trying to segregate a .tiff file (over 700 slides) and I would like to separete the outer black point. When I aply a threshold filter for the darkest colours, Avizo identify outer zones as porosity and, it isn´t true. Anybody can help me to separate the real porosity from the false one??

Another question related to the previous one. I would like to made a 3D volume rendering of the whole sample and, again, I have the problem of the outher zones. I have tried to create a manual 3D volume (cilinder, box...), but I would like to create a 3D volume that will be adjust to the edges of my sample. Can anybody help me with this??

I woukld be delighted if anybody could help me with any of this situations.