Well, monochrome is 1bpp, so it makes the raw image about 8Mbit or 1MB. The rest you'd only be able to determine empirically, and it depends quite a bit on wha

Well, monochrome is 1bpp, so it makes the raw image about 8Mbit or 1MB. The rest you'd only be able to determine empirically, and it depends quite a bit on what you're scanning and the scan quality. "Noisy" images, including poor-quality scans or scans of halftones, don't compress well, but a crisp scan of high-contrast text or line art will be a fraction of that 1MB even with a trivial compression scheme like RLE. If you store as a TIFF with LZW, or something proprietary but similar to that, you're probably talking about an average of 200kB or less for a high-resolution scan. And this is assuming a fairly generous size/speed tradeoff, since you have a local hard drive to burn. I've seen huge document archives that go the other way (scan at lower resolutions, compress hard) that average 30-50kB/page.