Bouler added these comments in the current discussion du jour ...

Paint Shop Pro is my Friend.
This picture has a better quality.

Noise can easily double or even triple the compressed size of a JPEG
because the "lossy" compression algorithm can't. In this case, assuming
the 1.5MB other one is the basically as-scanned version, I think some
more time in PSP 9 could reduce the noise even further, enhance the
sharpness/detail from what DCNR does a 400-grit sandpaper job to, and at
1800 x 1209 maybe the size could get down to under 600KB. I don't know if
your scanner does or doesn't have a descreen function, if it does, use
it. Also, a long-time a.b.p.autos Cyber friend that goes by 24Bit® taught
me to "over scan" by upping the DPI I thought I needed to get a given
pixel size for the scan by at least 2X, preferably 3X or even more so
long as the optical limit of the scanner isn't reached (at which time,
going any higher on the DPI actually reduces the quality). After getting
a 3X scan at, in this case, maybe 3500 x 2500, one would reduce to no
more than 1600 x 1200 which tends to "compress" out some of the noise
through the mathematical resampling process. Thus, DCNR has a much easier
time and you can use lower smoothing values which in turn preserves more
of the detail and sharpness.

--
HP, aka Jerry

"If it waddles like a duck and quacks like a duck, it must be a duck"