It's a combination of factors:
the image HAS jpeg compression artifacts all over, but it's NOT the only explanation for that specific image:
jpeg compression does NOT makes appear the lunar soil blue:
jpeg compression does NOT creates the dots that you can observe in both, background and module's shadow in the brightened/contrasted version

jpeg compression does NOT create a blue blur effect around the shapes, see module's silohuette
all this stuff cannot be explained just with jpeg compression: these are issues encountered during the scan from the roll Hasselblad, or even before,
or even after: if you would enhance that specific scan print in lossless format, these three issues would be still visible, and there's a huge amount
of similar issues in apollo images.
All the versions of this image should have been scanned from the same frame of the same roll, in different ways: and we don't know what type of scan
has been made for the special edition (IF it is a scan), nor if it is a second, third, fourth generation copy, and HOW it has been created the copy,
and we haven't anything with which to compare it from the same area.
So yes, jpeg compression artifacts, but NOT only.
www.hq.nasa.gov...
[edit on 5/8/2008 by internos]