How do i fix convex hull on rib part alone in input image

CT Chest image is my input. I want to fix convex hull on rib cage part. I have separated rib cage part. Then How do i fix convex hull on it? Please help me, I don't know how to proceed this (I'm supposed to use morphological operations).

Answer 1

[Walter Roberson]

http://www.mathworks.com/help/matlab/ref/convhull.html

%note that row number corresponds to Y, not X

[Y, X] = find(RibCagePart);
K = convhull(X, Y);
hullX = X(K);
hullY = Y(K);

hullrows = hullY;
hullcols = hullX;

%to visualize
imagesc(RibCagePart);
plot(hullX, hullY, 'r')

[revathi t]

Thanks for your code Sir. It works good. Now i have convex hull fitted image. Is there any way to find lambda1,2 & 3 values from this image? (Because I need these values for further processing. Task is like removing scapula bone from this ribcage convex hull image. Here tubular shape will be considered as rib and plate like shape as scapula. formulas are available. But i need lambda values for substitution. Finally i have to find ribcage volume without scapula)