I think we are just seeing JPEG compression artifacts. Here is the same image twice, scanned and saved at 300dpi, but saved once at high compression and again at low:
 Low compression (278.8 KB) |
 High compression (57.94 KB) |
The two images look fairly similar, although it is easier to pick out the colored threads embedded in the paper in the low-compression image. If you now go in on a detail, say "This note...", you can see the tradeoff of quality vs file size:
 Detail of low-compression JPEG |
 Detail of high-compression JPEG |
Now, for comparison, here's some of that printing at 1200dpi:
It should be clear that the scanning and image compression add enough uncertainty that you really can't tell what went on with the image. Obama needs to authorize the Hawaii authorities to post the real one on the net.