Hi James,
Fair enough.
However I would still be quite interested to see how different the
results are from the originals and the compressed versions. If the
differences were pretty minor (i.e. not really noticeable) then I
would certainly have a good look at the mp3 version.
Also it would make my data storage situation a little easier, at least
what I use for routine testing. Worth a go?
Cheerio,
Graeme
On 8 November 2011 18:19, James Holton <jmhol...@lbl.gov> wrote:
>
> At the risk of putting this thread back on-topic, my original question was
> not "should I just lossfully compress my images and throw away the
> originals". My question was:
>
> "would you download the compressed images first?"
>
> So far, noone has really answered it.
>
> I think it is obvious that of course we would RATHER have the original data,
> but if access to the original data is "slow" (by a factor of 30 at best)
> then can the "mp3 version" of diffraction data play a useful role in YOUR
> work?
>
> Taking Graeme's request from a different thread as an example, he would like
> to see stuff in P21 with a 90 degree beta angle. There are currently ~609
> examples of this in the PDB. So, I ask again: "which one would you download
> first?". 1aip? (It is first alphabetically). Then again, if you just email
> the corresponding authors of all 609 papers, the response rate alone might
> whittle the number of datasets to deal with down to less than 10. Perhaps
> even less than 1.
>
> -James Holton
> MAD Scientist
>
>
> On 11/8/2011 5:17 AM, Graeme Winter wrote:
>>
>> 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
>>>>
>
>
