Storing black and white scanned document images is even odder, however. Consider these results from PDFs generated by my Brother MFC-7820N document scanner (1 page, 300 dpi, b&w). In each case I saved from OS X preview:
- Original PDF: 132kb
- PNG: 155kb
- JPEG 2000 lossless: 296kb
- JPEG 2000 good quality: 380kb
- JPEG: 328 kb (artifact can be seen)
- TIFF zip compression: 220kb
- TIFF alternative compression: 216kb
Interesting that JPEG 2000 lossy is almost 40% larger than lossless for a b&w image. I thought I'd get better results there.
PNG, as always, does very well for lossless compression. A shame they never put any $!#$% metadata into the file specification!
Note that iPhoto will handle all of those image formats except PDF.