Hey Zuy,
I don't think you can concatenate statements in matlab using '&&' - that is a logical operator, the kind that is used mostly within an if condition. I presume that the error you are receiving is related to that; please try to post the actual error message when you ask a question on the community so that we can understand your problem better. This should increase your chances of getting a response manifold, in my experience.
Here's a solution you can try out:
You need to use a copy of the image before changing colors, otherwise you'll be overwriting the first change when you make the second one, and produce all 0's (or all 1's).
% 'I' hold the binarized image.
temp = I;
I(temp==1)=0;
I(temp==0)=1;
Hope it Helps!
