Quantify connectivity in a 3D matrix containing ones and zeros representing voids in a microstructure

I have a 3D matrix (100x100x100) full of either ones or zeros. Each place in the matrix represents a 1x1x1 micron "cube," essentially, in a microstructure of a hydrated cement paste. A "1" means this space is occupied by a pore, and a "0" means it is not. I'm trying to walk though this matrix and quantify the number of particles that are connected. That is, there may be 600,000 ones ("pores") in this matrix, but a number of them are connected in 1, 2, or 3 direction, meaning a significantly smaller number of total pores. Any help on how I might walk though this matrix narrow down the number of pores I have would be greatly appreciated!

Answer 1

[Bruno Luong]

If you have image processing toolbox, check out this function http://www.mathworks.com/help/toolbox/images/ref/bwlabeln.html

Answer 2

[Nathan]

Thanks! That seems to be working well for me.