Pixels for digits

Hi,

I'm needing a script (or whatever it takes) to convert a bitmap file in a Text file with a digit associated to each pixel. For example, a 3x3 pixel image with a black (1) square and a white (0) dot in the middle will be converted to a txt file with the following content:

111
101
111

If anybody could point me to any plugin or program that does it or could point how to do it... I'll be very grateful.

Thanks,
Felipe.