[dunham]

I like the idea, but DjVu seems to be very proprietary / single vendor and not in widespread use. This has made me reluctant to use it for archival purposes (vs say PDF, which has its own issues, but feels slightly more future proof to me).

I think PDF can cover pretty much the same ground with JBig and Jpeg2k. (And I believe archive.org is doing that.) But I don't know of any open source code to do the segmentation / encoding. (You have to split the bitmap from the background for jbig / jpeg encoding.)

[pwg]

There is an open-source DjVu library as well:

http://djvu.sourceforge.net/

Whether that makes the format "widespread" enough for your use case is of course your decision to make.

[mcguire]

The major source for DjVu files I have run across is the Internet Archive's book scanning. (Weirdly, I can't find any examples.) They're usually smaller than PDFs.