MATLAB: How to compute regions of matrix

matrix areamatrix region

Hi all
Let's say we have the following matrix:
    0 0 0 0 0 0
    0 1 0 0 0 0
    1 1 0 0 0 0
    1 1 0 0 0 0
    0 0 0 0 0 0
    0 0 0 1 1 1
    0 0 0 0 1 1
    0 0 0 0 0 0
I want to calculate the size of every connected region of 1s and also get the corresponding matrix elements of each region. The size should be computed as (width + heigth) / 2.
In the example the bottom left region would have size (2 + 3) / 2 and the bottom right region would have size (3 + 2) / 2.
Additional to the size of the regions I also want the corresponding entries of the regions, i.e. region 1 has entries (2,2), (3,1), (3,2) and so on.
How can this be done in Matlab?
I'm looking forward for the answers and wish everybody all the best.

Best Answer

Trivial, provided you have the image processing toolbox. Take a look at BWLABEL and REGIONPROPS
M = [ 0 0 0 0 0 0
    0 1 0 0 0 0
    1 1 0 0 0 0
    1 1 0 0 0 0
    0 0 0 0 0 0
    0 0 0 1 1 1
    0 0 0 0 1 1
    0 0 0 0 0 0]
P = regionprops(bwlabel(M),'boundingbox')
The last two values of the field BoudingBox will give you the height and the width of each connected region.
Related Question