Um, but isn't Crystallograpy based on a series of
one-way computational processes:
photons -> images
images -> {struture factors, symmetry}
{structure factors, symmetry, chemistry} -> solution
{structure factors, symmetry, chemistry, solution}
-> refined solution
At each stage we tolerate a certain amount of noise
in "going backwards". Certainly it is desirable to
have the "original data" to be able to go forwards,
but until the arrival of pixel array detectors, we
were very far from having the true original data,
and even pixel array detectors don't capture every
single photon.
I am not recommending lossy compressed images as
a perfect replacement for lossless compressed images,
any more than I would recommend structure factors
are a replacement for images. It would be nice
if we all had large budgets, huge storage capacity
and high network speeds and if somebody would repeal
the speed of light and other physical constraints, so that
engineering compromises were never necessary, but as
James has noted, accepting such engineering compromises
has been of great value to our colleagues who work
with the massive image streams of the entertainment
industry. Without lossy compression, we would not
have the _higher_ image quality we now enjoy in the
less-than-perfectly-faithful HDTV world that has replaced
the highly faithful, but lower capacity, NTSC/PAL world.
Please, in this, let us not allow the perfect to be
the enemy of the good. James is proposing something
good.
Regards,
Herbert
=====================================================
Herbert J. Bernstein
Professor of Mathematics and Computer Science
Dowling College, Kramer Science Center, KSC 121
Idle Hour Blvd, Oakdale, NY, 11769
+1-631-244-3035
y...@dowling.edu
=====================================================
On Tue, 8 Nov 2011, Harry Powell wrote:
Hi
I am not a fan
of one-way computational processes with unique data.
Thoughts anyone?
Cheerio,
Graeme
I agree.
Harry
--
Dr Harry Powell, MRC Laboratory of Molecular Biology, MRC Centre, Hills Road,
Cambridge, CB2 0QH
http://www.iucr.org/resources/commissions/crystallographic-computing/schools/mieres2011
