Filtering binary image object based on area

I have a binary image below:

and the four straight objects are trees which i want to keep and the blob below is an unwanted object in the binary image. I'm using bwareafilt to extract only the objects i want, which in this case would be the four trees. However, by using:

regionprops(binimg, 'Area')

I get:

and the unfortunate thing is that the area of fourth tree (3557), is lesser than the area of the unwanted blob below. Hence if i use:

newbw = bwareafilt(binimg, [3900 5000])

the fourth tree will be filtered out leaving only:

If the area of the unwanted object is larger than the object i want to keep in the binary image, how do i handle this?

Answer 1

[darova]

What about centroid?

I = imread('Capture.png');
I1 = rgb2gray(I);
L = bwlabel(I1);
pp = regionprops(L,'centroid');
xy = cat(1, pp.Centroid);       % concatenation

[~,n] = max(xy(:,2));           % find bottom label
I1(L==n) = 0;                   % fill  bottom
imshow(I1)
hold on
plot(xy(:,1),xy(:,2),'or')
hold off