N00b question on graphics

Please excuse my n00bness about MATLAB but I could do with some help with something. As part of a coursework I am currently working on, I need to have produced a 20x20 matrix which contains a picture in binary format (so only 0's and 1's). I have created this matrix and the only information I can find on making it draw a picture is to use the function image(A) where A is the matrix. WHen I do this, it just prints a black block as the image with no white on it.

Is there another way to print this image?

This is just a small part of the coursework btw, I am supposed to add noise to the image and use svd to improve it. These parts I have no problems with.

Thanks in advance, Chris