Get the coordinates of a curve

I have a binary figure. I'd like to find the contour of the bright part. I used h=contour(mat,[x,x]); However, I do not need MATLAB to plot h. I just need the value of h. Is there a proper parameter of contour or another matlab function?

Answer 1

[Walter Roberson]

You can use contourc to do the contour calculations without displaying any contour.

I would suggest to you that regionprops() would likely be more appropriate than contour(). contour() on a binary image is just going to look like a morophological filtering of the binary image.

[Dayong]

Thanks for your help.

Answer 2

[Image Analyst]

I'm not sure why you think you need h, the handle to a contour group. Don't you think either bwboundaries() or bwperim() would give you what you want?

[Dayong]

Thank you all the same. However, I need the pixels of the boundary arranged counter-clockwise or clockwise. contour() and contourc() are better choices.

[Walter Roberson]

http://www.mathworks.com/help/images/ref/bwtraceboundary.html allows you to select clockwise vs counter-clockwise.

[Dayong]

Oh,sorry. It's my fault.

[Image Analyst]

Are you saying that bwboundaries does not give coordinates in an adjacent CW or CCW order? That they're in raster scan order or something? I'm pretty sure that is not the case.