omitting objects dependent on their area in binary image

Hi could you please help me , i am trying to remove any object has area more than 500, after drawing bounding box for it, below my code and image:

    % %%
v=x11;% where x11 is image 
[lab1 num1] =bwlabel(x11)
BW2=regionprops(lab1,'Area') ;% calculate the area for each object in dia
 for y =1 : num1
     [rl cl]=find(lab1== y)  
 if (BW2.Area(y)) > = 500
    { 
      lab1(BW2.Area(y)) == 0;
     }
    end
figure ,imshow(lab1)
title(' object');

    %%Measure properties of image regions
propied=regionprops(v,'BoundingBox');
BW2=regionprops(v,'Area');% calculate the area for each object in dia
hold on
%%Plot Bounding Box
for n=1:size(propied,1)    
    rectangle('Position',propied(n).BoundingBox,'EdgeColor','g','LineWidth',2)
     figure ,imshow(v)  
end 

end

Answer 1

[Guillaume]

Using BW2 as a variable name for the output of regionprops is extremely misleading. BW2 implies a binary image which is not at all what regionprops returns.

Anyway, the simplest way to filter objects by area is to use bwareafilt before the call to regionprops. In your case:

BW2 = bwareafilt(BW, [1 499]);

[lotus whit]

Thank you a lot