Connect disconnected boundaries of objects?

Hello,

I have segmented a histology slide of a lung and I am trying to label individual airways using bwlabel. The segmentation works adequately so far, however some airways have gaps in their boundary lines. I have tried using morphological closing to close the gaps, but it doesn't work with small structuring elements and using larger SEs will result in losing smaller airways.

Any suggestions on how to do this? I have attached the original and segmented versions as well as a zoomed in version to a particular boundary I would like to close.

Answer 1

[HANTZ PETER B THERMORIS]

% Try to use the erosion ('imerode') first on your image with a different structure element. 
% Then, use the closing with an other srtucture element.