curvature calculation
curvature calculation
(OP)
I have an image smoothed using Gaussian smoothing technique. The edges of the object in this image has been detected. Next, i would like to calculate the curavture of the edges. How can do so using Matlab 6 ? thanks.





RE: curvature calculation
hope this is useful.
Sonya
RE: curvature calculation
thanks for the reply. I had actually tried using polyfit to do so. But the problem is : there are multiple points occur with the same x or with the same y. So, how can i eliminate this ?? thanks
RE: curvature calculation
1)Use contour to get contineous lines.
2) Find turning points by chacking sign(diff(x)) for each line and split it to single valued lines.
Joe
BSTEX - Equation viewer for Matlab
http://www.geocities.com/bstex2001
RE: curvature calculation
There are a lot of circular objects which are the objects of my interest. So, I dun think using contour can help me to draw the the continuoes line for all the circular objects where some are connected and others are not. Moreover, I really don't know how many line i need to draw.
I am actually thinking whether i can just count the curvature at each of the edge point that i found from the Canny Edge Detector method. Is there any way for me to do so ?? Thanks.
RE: curvature calculation
Sure you can do it because any 3 points defines a unique circle that its radius can be associated with the curvature at the mid point. This is a simple Euclidian geometry. The only thing is that:
1) You have to make sure that any point has only 2 neighbors (use 'thin'), and to check nearest neighbors.
2) The result will be very 'noisy'.(You may try to smooth the curvature result after computation.
Joe
BSTEX - Equation viewer for Matlab
http://www.geocities.com/bstex2001
RE: curvature calculation
If i do have any preliminary knowledge on the radius of the circular objects, is there any way for me to calculate the curvature at the edge point ? thanks
RE: curvature calculation
If i do NOT have any preliminary knowledge on the radius of the circular objects, is there any way for me to calculate the curvature at the edge point ? thanks