How can I smooth a 2D boundary ?

Hello, I have a N*2 matrix of x,y coordinates. I need to smooth the boundary. I tried with interp2 but I didn't get something nice.

Answer 1

[Image Analyst]

Lots of ways. One way is to use splines:

Another way is to use a Savitzky-Golay filter.

I'm attaching demos for each of these methods.

[Sleh Eddine Brika]

Thank you

[Bram Mast]

After you have extracted the boundary and applied a smoothing filter on the coordinates, which command can you use to extract information about de boundary (area, perimeter, ...) ?

[Thiago Motta]

That would be regionProps

[Image Analyst]

mask = poly2mask(x, y, rows, columns);
props = regionprops(mask, 'Area', 'Perimeter');

props is a structure or structure array where each structure will have an Area field, and a Perimeter field.