Easier / Faster Way???

[FinePointImages]

Hi all,
I'm new to the site, quite interesting so far.
Hopefully one of you can help with this...

I have a client who is an artist. She has a project she does at least once a year involving sound waves. She records her voice, and the sound technician then is able to output a 72 dpi 2" graph of the sound wave. (So very low res. only)
It's basically square blocks of black on a white background. (Like a bar graph)

The question / challenge I have is recreating that sound wave in a high res carpet sized image. (Like at least 6 feet lon 30" high) at 150dpi. It has to be sharp, because she uses it for other things as well.
I've been doing it manually with the path tool (rectangle in add mode with a fixed size) This works great because I can then resize the path to an unlimited size with no quality loss. But I'm basically selecting each vertical bar on the low res, and this is quite time consuming.
I have tried various other methods of selection, then creating a path...never works because the selection is always low res. If I try to resize it, the bars in the graph are not as sharp...

So...Does anyone know a method that I can get a selection of a greyscale or B&W low res document, and create a sharp scaleable path with nice square corners?

I've attached a sample of what I usually get (except it is usally 20x the length!)
Any help / suggestions would be great!

Thanks,

Greg
Fine Point Imaging

[Doug Nelson]

I'd fire up Illustrator and use its vector conversion function. Then you could scale to billboard size.