show a simple rectangle

i just need to show a rectangle(square) with any color in a camera videostream, then i need to crop the snapshot according inside the rectangle in the video (size 180x200), can you guys help me? here are the few codes been working:

vid = videoinput('winvideo', 1, 'YUY2_320x240');
preview(vid);
            for ii=3:-1:1
                pause(1);
            end
img = getsnapshot(vid);
figure,imshow(img);
BW = imcrop(img,[75 68 180 200]);
imshow(BW);

thank you!!

Answer 1

[Image Analyst]

Did you try "hold on" and rectangle() to show the rectangle over your live video? Your code seems to go live for just two seconds and then snap, crop, and display an image. What is the problem you are having?

[Izzo]

i just want to display a rectangle with 180x200 size in my live video then snap and crop it, that is all

[Jan]

And what is the problem you are having?

[Izzo]

the problem is i cant do it, i just asking for someone who might knows