Image Processing RegionProp help

I have convert vedio into array of matrix frames , converting them into a binary image and using regionprop I have found coordinates of white region. What I wanted to find out is a coordinates of end point of a white region (e.g. it would returns end point of this bw image is x=something and at that x y=something)

regionprop command

%%
regionstats = regionprops(myBarray{1,1}, 'all');
[~, largestidx] = max([regionstats.Area]); %find index of largest region
x=regionstats(largestidx).BoundingBox;    %coordinate of bounding box of largest region
y=regionstats(largestidx).PixelList;      %coordinate of all pixels in the region as a matrix

As y return values of all the xy coordinates of white region.

I'm attacting a picture of desired output

[KSSV]

From the (x,y) pick up the maximum of x, and it's respective y....wont it give you waht you want?