How to find steepest descent path for a peaks graph.

I've been given this task, but when I try to find the minimum of these indexes: (i-1, j), (i + 1, j), (i, j-1), (i, j + 1). The min function doesn't work for me.

Find indices (i, j) of the highest point, i.e. the point with the highest z-value. (Hint: Use find). Save x, y and z values of (i, j) of each path-vector, which at this stage only has one item each.

2. Algorithm steepest descent: While point (i, j) does not lie along an edge:

a. neighbor point having the lowest z-value. By neighbors means those points that have index (i-1, j), (i + 1, j), (i, j-1), (i, j + 1).

b. If this neighboring point's z-value is lower than Z (i, j):

I. Do this next point about the current point (i, j).

II. Add the x, y and z values of (i, j) of trail vectors so that they increase their lengths with one item each. Otherwise: Exit algorithm.

c. Return to the top of the algorithm

Answer 1

[Image Analyst]

imerode is a local min operator. To look at just the 4-connected pixels like you said, you use a cross kernel:

localMins = imerode(grayImage, [0,1,0;1,0,1;0,1,0]);