MATLAB: How to remove the excess object detected? Often the code finds more mouths and I want take only one, the one which is belower. Thanks.

FDetect = vision.CascadeObjectDetector;

I = imread ('Test W.jpg');

figure(1),imshow(I);

title ('…')

BB = step(FDetect,I);

figure(2),

imshow (I); hold on

for i = 1:size(BB,1)

rectangle('Position',BB(i,:),'LineWidth',5,'LineStyle','-','EdgeColor','r');

end

title ('…');

hold off;

NoseDetect = vision.CascadeObjectDetector('Nose','MergeThreshold',16);

BB=step(NoseDetect,I);

figure(3),

imshow(I);hold on

for i = 1:size(BB,1)

rectangle('Position',BB(i,:),'LineWidth',4,'LineStyle','-','EdgeColor','b');

end

title ('…');

hold off;

MouthDetect = vision.CascadeObjectDetector('Mouth','MergeThreshold',16);

BB=step(MouthDetect,I);

figure(4),

imshow(I);hold on

for i = 1:size(BB,1)

rectangle('Position',BB(i,:),'LineWidth',4,'LineStyle','-','EdgeColor','g');

end

title ('f…');

hold off;

EyeDetect=vision.CascadeObjectDetector('EyePairBig');

BB=step(EyeDetect,I);

figure,imshow(I);

figure(5),

imshow(I); hold on

for i = 1:size(BB,1)

rectangle('Position',BB(i,:),'LineWidth',4,'LineStyle','-','EdgeColor','r');

end

title ('…');

hold off;