Dear Herbert,
Sorry, the point I was getting at was that the process is one way, but
if it is also *destructive* i.e. the original "master" is not
available then I would not be happy. If the master copy of what was
actually recorded is available from a tape someplace perhaps not all
that quickly then to my mind that's fine.
When we go from images to intensities, the images still exist. And by
and large the intensities are useful enough that you don't go back to
the images again. This is worth investigating I believe, which is why
I made that proposal.
Mostly I listen to mp3's as they're convenient, but I still buy CD's
not direct off e.g. itunes, and yes a H264 compressed video stream is
much nicer to watch than VHS.
Best wishes,
Graeme
On 8 November 2011 12:17, Herbert J. Bernstein
<y...@bernstein-plus-sons.com> wrote:
> 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
>>
>
