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From: dorayme on 1 Jul 2010 19:04
In article <i0i4jh$cnc$1(a)news.eternal-september.org>,
Wes Groleau <Groleau+news(a)FreeShell.org> wrote:

> On 07-01-2010 03:12, dorayme wrote:
> > Who would? I have yet to see a human spot any critical difference
> > between a tiff and a jpg that is not further compressed than max
> > that could possibly be of relevance to diagnosis. Most X-rays neg
>
> What is your criteria for determining whether something
> “could possibly be of relevance to diagnosis”?
>
> You probably are judging the image quality based on a lack of
> understanding what you are looking at.

I am not judging any x-ray in particular. Perhaps you mean that
there may be things so fine and subtle that a medical expert
would be able to spot the absence of something critical in a jpg
that was compressed as little as it is normally possible to
compress a jpg by comparing it with a tiff.

We can chatter here or we could as best as we can put our money
where our mouths are by setting up a bet. I will do the jpging,
you supply the tiff or whatever file is richly informed in your
opinion and we will see if experts medicos can tell the important
medically relevant differences. If they can't, I get your dough.
Please get your accountant to make me a full list of all your
assets before we begin.

> As for compression,
> I acknowledge that for most images I've looked at (not xrays),
> I can lower the quality ...

It is not very relevant to be talking high compression. Of course
some compressions will start to impact on relevant information.

>
> What is the meaning of “further compressed than max”?

In most image software that you can buy or use there are levels
of compression. Either you use percentages or keywords or
sliders. The scales are either in terms of compression or in
terms of quality. Take sliders. Sliders come to stop at the ends
and you cannot go beyond them. For example, you can compress no
further than the slider allows. You cannot compress further and
further to infinity so that a nice picture of Doris Day at her
best turns into a picture of Roger Rabbit. At the other end you
cannot go beyond max quality or least compression. But even at
this latter end, you get great savings in file size with no loss
of quality that usually matters to anyone.

> I'm not a jpeg expert, but GraphicConverter allows me
> to set quality at zero percent.

Not relevant. It is not that end of the scale that the argument
depends on (you keen on setting up straw men?)

> At 72 ppi (unacceptable
> resolution for xrays), a zero, which GraphicConverter
> allows, reduced a 1.4 MB 1930 census image to 161 KB.
> Text was still decipherable, but not pretty.
>
> I can reduce the size further by asking for a resolution
> of five pixels per inch.

Not relevant. I am not the sort of idiot who is claiming one
can't lose important quality by jpging. I am an idiot of a
completely different kind.

--
dorayme
From: Wes Groleau on 1 Jul 2010 19:11
On 07-01-2010 19:04, dorayme wrote:
>> > I'm not a jpeg expert, but GraphicConverter allows me
>> > to set quality at zero percent.
> Not relevant. It is not that end of the scale that the argument
> depends on (you keen on setting up straw men?)

No, I'd rather knock them down. You said
“further compressed than max” without saying max what.
I asked what you meant since (obviously) I did not
understand what you meant.

--
Wes Groleau

Measure with a micrometer, mark with chalk, and cut with an axe.
From: Wes Groleau on 1 Jul 2010 19:36
On 06-30-2010 13:15, isw wrote:
> Tom Stiller<tom_stiller(a)yahoo.com> wrote:
>> Jason S<jasonsavlov(a)me.com> wrote:
>>> Why does this sound way more complicated than it probably is? And why
>>> on earth does your veterinarian put the images in a windows executable
>>> file? Why not just put the images in folders as PNG or JPG or something
>>> easily accessible?
>>>
>> PNG is OK but why would one store X-ray images in a lossy image format
>> like JPG?
>
> Because if you do it right, you save considerable space, and it's not
> lossy enough to matter?

I am certain that the executable is merely a viewer and that JPEGs are
somewhere on the disk, _maybe_ PNG. I suspect JPEG because that's what
these programs typically do. I am certain they are not TIFFs because
like it or not, Internet Explorer Six is still about half the browsers
out there, and it can't do TIFF. Think what you will about the makers
of the software, but they're not _that_ stupid.

As dorayme has been hinting at “lossy” is both vague and variable, and
unless you apply a LOT of compression, no one can tell the difference.
Whether the difference that isn't noticed can hurt someone, I don't
know. Anyone aware of a malpractice suit in which the use of a lossy
image format was material?

I am fairly certain that the choice of JPEG had _nothing_ to do with
medical standard of care. More likely to produce the CD, the equipment
maker took whatever type of image they use internally and dumped it
into the same off-the-shelf software you get when you develop your
birthday photos at Walmart or Walgreens or CVS or Meijer or ....

--
Wes Groleau

Hostility to TPRS
http://Ideas.Lang-Learn.us/barrett?itemid=1596
From: dorayme on 1 Jul 2010 19:58
In article <i0j7bo$jug$1(a)news.eternal-september.org>,
Wes Groleau <Groleau+news(a)FreeShell.org> wrote:

> On 07-01-2010 19:04, dorayme wrote:
> >> > I'm not a jpeg expert, but GraphicConverter allows me
> >> > to set quality at zero percent.
> > Not relevant. It is not that end of the scale that the argument
> > depends on (you keen on setting up straw men?)
>
> No, I'd rather knock them down. You said
> “further compressed than max” without saying max what.
> I asked what you meant since (obviously) I did not
> understand what you meant.

There are two ends of the scale, either in quality or in
compression. I assumed *in the context of the discussion* that
people would know that I was talking the least compression,
highest (max) quality end. I assumed (silly me - this is
*usenet*) that a principle of charity would operate whereby it
would be obvious that *at the very least* I was not talking the
highest compression end where one can turn a lovely Doris Day in
her heyday into a blurred mess.

(btw in The Pajama Game, which I have just revisited, there are
some fabulous song and dance routines... get to see it, Wes.)

--
dorayme
From: Wes Groleau on 1 Jul 2010 22:31
On 07-01-2010 19:58, dorayme wrote:
> *usenet*) that a principle of charity would operate whereby it
> would be obvious that*at the very least* I was not talking the

:-) Well, as noted, it wasn't obvious to me. And what does charity
have to do with it, other than you trying to get all my asses.
Huh? Oh, _assets_

> highest compression end where one can turn a lovely Doris Day in
> her heyday into a blurred mess.
> (btw in The Pajama Game, which I have just revisited, there are
> some fabulous song and dance routines... get to see it, Wes.)

Saw it long ago—my late wife was a major fan of Doris Day, Hayley Mills,
Christopher Plummer, and Roger Whitaker.

--
Wes Groleau

Why is this word disappearing?
http://Ideas.Lang-Learn.us/barrett?itemid=1581
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