problem to get xy contour coordinates

Hi, I tried to get contour coordinates but it seems that i'm using the wrong solutions, after segementing my image i want to get x y coordinates of the contour here is the image

i tried to use the

C2xyz function then convert it with cell2mat as you can see here

o1=cell2mat  ( C2xyz (contour(FC>thresh)))% contour seeds
[ro,wo]=size(o1)

so the size gives 4750 in ro and 1 wo the image size is 128x128 so the coordinates must be in this interval , i've also tried this code

[cx,cy]=(C2xyz(contour(FC >thresh)));

   a1 = str2double(cell2mat(a))
   xc = str2double(cell2mat(cx))
   yc =  str2num(cell2mat(cy))
   xmin = min(xc);
   ymin = min(yc);

   B=bwboundaries(a1);
   B{1,1}(1,:) = [];

   rows = B{1,1}(:,2);
   cols = B{1,1}(:,1);

   x = (rows-1)*0.5+xmin
   y = (cols-1)*0.5+ymin

but it gives NaN values, i will be thankful if someone knows how to extract x y coorinates from the contour i've seen that there is get 'Xdata' is used for fig file , i don't know if generating my plot as fig file then use get ('Xdata') is a solution

thanks in advance,