how to apply convex hull algorithm in MATLAB on gray scale image

Question

I want to apply convex Hull in MATLAB on gray scale image but regionprop and other built-in functions that are provided on net are not working please help me, to find objects from images that have less connectivity between pixels.

Answer 1

First, you need to create a binary image out of your grayscale image. One option is by thresholding:

t=imgraythresh(YourGrayImage);
bw=im2bw(YourGrayImage, t);

Then obtain the convex hull like this:

ConvHull=bwconvhull(bw,'union')

Or, if you want the convex hull of all individual objects:

ConvHull=bwconvhull(bw,'objects')