Create Contour Plot of Grayscale Image
This example shows how to create a contour plot of an image. A contour is a path in an image along which the image intensity values are equal to a constant. You can create a contour plot of the data in a grayscale image using the
imcontour function. This function is similar to the
contour function in MATLAB®, but it automatically sets up the axes so their orientation and aspect ratio match the image.
Read and display a grayscale image.
I = imread("moon.tif"); imshow(I)
Create a contour plot of the image with ten contour levels using
[C,h] = imcontour(I,10);
Display the levels that the
imcontour function selected.
ans = 1×10 23 46 69 92 115 138 161 184 207 230
To label the levels of the contours, use the
clabel function. Zoom in to see the contour details.
clabel(C,h) xlim([160 200]) ylim([360 400])
Display a single contour at level 128.