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matlabmatlab-figurecontour

How to group the green contour and the yellow contour?

I'm using imcontour in MATLAB to get the contour of some image. The resulting image is as follow. Is there any way that I can pick out the green contour together as a group, and the yellow contour together as a group?

fig.1

Solution

  • The good news is that your data are already grouped. Assuming you have an image/matrix I and you are doing something like imcontour(I, 2), you have just to use [C, h] = imcontour(I, 2). C is a ContourMatrix, which contains (type help clabel) the "contour line definitions, returned as a two-row matrix. Each contour line in the plot has an associated definition. If there are a total of N contour lines in the plot, then the contour matrix consists of N definitions (N=2 in your example):

    C = [C(1) C(2)...C(k)...C(N)]

    Each contour line definition follows this pattern:

    C(k) = [level   x(1) x(2) ... x(numxy)
        numxy   y(1) y(2) ... y(numxy) ]