¿can someone tell me how can i threshold this grayscale image to later count the white squares?

i'm using an usb camera and taking snapshots from it, but i cant figure it out how to threshold the image to get only the white squares, then im going to count them but i always get noise. @Image Analyst i need your help! i upload photos of the original RGB picture and the gray scale ones. this is the code:

im=snapshot(vid); im=imcrop(ima,roi); imG=rgb2gray(im); imG=imadjust(imG); imB=im2bw(imagenG2,0.72); subplot(3,1,1); imshow(im); subplot(3,1,2); imshow(imG); subplot(3,1,3); imshow(imB);

Answer 1

[Nate Ellingson]

The best way I see to do this:

Use "imcontour" on your thresholded image, and then figure out how to parse the "C" output argument of this function (OpenCV's function is a little easier to use)

Find the area of each contour with a function like polyarea.

Then only count areas large enough to be one of the white squares.