Edge detection + binary mask

I want to create a mask of a thresholded head/neck dicom serie based on detection of the black white boundary. So i want to detect the transition form black to white and determine the positions of this transition after which i would like to create a mask. Does anybody has a suggestion for a method to preform this?

Answer 1

[Image Analyst]

You don't need to do edge detection - not sure who told you that. You simply need to do thresholding and hole filling.

binaryImage = grayImage > 50; % or whatever gray level the background is.
mask = imfill(binaryImage, 'holes');