Controlling the sizes of particle analysis (counting dots)

I am trying to count the number of dots in an image (think upwards 3000 points), but I'd like to have a size range so that matlab will only count particles in that range and disclude all the others. Here is my current code:

figure, imshow (A);
B = bwboundaries(A);
imshow(A)
text(10,10,strcat('\color{green}Objects Found:',num2str(length(B))))
hold on
drawnow; % Force display to update immediately.
end

thank you!