Extracting points for sharp curvature from signed distance function array

I have a signed distance array, extracted from a black-and-white bitmap. The shape described by the bitmap is arbitrary, and could contain concave or convex curvature of varying scales. I am interested in extracting the position of corners that are sharper than a certain amount. I'm frankly not sure how to define that sharpness here; what I care about is 'shoving' a circle of a defined radius into that corner, and for the corner in total to be larger than that circle (in other words, I don't want it reporting every single rasterisation of the bitmap):

1. identifying if any convex curvatures' radius is less a code-defined radius of curvature limit
2. calculating what coordinate in the bitmap represents the centrepoint of the code-defined radius of curvature limit for that corner, and then
3. to list any and all found sets of centerpoint coordinates in an array of format T= [x1, y1; x2, y2; .... xn, yn].

I'm obtaining my distance array and interpolation function as follows.

    X = imread("MeshTest01.bmp"); %load logical (1 or 0) bitmap
    A = imrotate(X,-90);
    E=edge(A);  % Edge finding of bitmap
    DistE = bwdist(E, "euclidean"); % signed distance function from edge 
    DistA = bwdist(A, "euclidean"); % signed distance function from whitespace

    D = DistE-2*DistA % Pixel-enumerative distance for signed distance function from material (outside is positive)
    D = double(D); %make array forced to Double so interpolation works correctly
    
    Fi = griddedInterpolant(D,'linear')
    
    fd=@(p) Fi(p);  %defining the interpolation function call

Answer 1

[Supraja]

You can use ‘ischange()’ function which detects abrupt changes in data.

The detailed documentation link for the same is given here: https://www.mathworks.com/help/matlab/ref/ischange.html?searchHighlight=ischange%20function&s_tid=srchtitle_ischange%20function_1

The sample code to use this function is as shown below:

f = @(x) 1-(x./sqrt(1+x.^2));                                   % Create Function 
x = linspace(-10, 10); 
y = f(x); 
changes = ischange(y, 'linear', 'SamplePoints', x); 
plot(x, y, '-', x(changes), y(changes), 'gp') 
grid on 
axis('equal') 
xlim([-2.5  2.5])