Skip to main content
news

Re: Lenses and sharpening

Floyd L. Davidson
SubjectRe: Lenses and sharpening
FromFloyd L. Davidson
Date2014-09-18 10:10 (2014-09-18 00:10)
Message-ID<87ha05uz6j.fld@barrow.com>
Client
Newsgroupsrec.photo.digital
FollowsSavageduck
FollowupsSandman (31m)
nospam (7h & 41m)

Savageduck <savageduck1@{REMOVESPAM}me.com>wrote:

Savageduck
On 2014-09-18 06:43:11 +0000, floyd@apaflo.com (Floyd L. Davidson) said:

Floyd L. Davidson
Savageduck <savageduck1@{REMOVESPAM}me.com>wrote:

Savageduck
On 2014-09-18 05:05:12 +0000, Eric Stevens <eric.stevens@sum.co.nz>said:

Eric Stevens
Yes, I found that text, but I don't think that it means what you seem to think it means. He wasn't claiming that JPEG is fully reversible: everybody knows that it isn't.

Savageduck
It means exactly what he intended it to mean. You are putting words in his mouth when you become his advocate and say that he wasnâEUR(Tm)t claiming that the JPEG is fully reversible. That is your spin on what he didnâEUR(Tm)t say.

Floyd L. Davidson
Yes it means exactly what I intended it to mean, which is very obvious to Eric, but not to you. There is no claim that JPEG is "fully reversible", or for that matter even partially reversible. All the BS is *you not being able to understand*.

Savageduck
The BS is the spin the two of you are putting on your actual statement.

Using standard terminalogy and discussion a commonly understood fact about the two algorithms to help someone decide which to use in given circumstances is not "spin".

The spin is when you insist on your own definitions, add words that were never implied much less stated, and then you try to beat up on your own staw man.

Eric Stevens
an alternative series of processes: 1. Sharpen image. 2. Save file as JPEG 3. Apply Gaussian blur to JPEG image to recover original image sharpness.

Floyd L. Davidson
Actually that is not quite what I said. I said the sharpen is reversible. I did not say fully reversible, I did not say the "original image sharpness" would be fully restored.

Savageduck
So your process isnâEUR(Tm)t actually reversible (or even non-destructive) so you could return to a true pre-adjustment state, just an illusion of a pre-adjustment state. I am glad we have cleared that up.

See previous discussion about integrity.

Floyd L. Davidson
Those are *your* claims! (In Eric's rendition.)

You still can't get past your own imagination...

Savageduck
However you challenged me to support my claim that he actually said that. Remember? Yo said yourself; âEURoeNo one who understood what we we trying to talk about would claim that a JPG conversion is a reversible process.âEUR âEUR¦but Floyd did, and Floyd knows what he is talking about, and he means what he says.

Floyd L. Davidson
Of course that is a total fabrication on your part. I said nothing about reversing a JPEG conversion.

Savageduck
Strange, here is what you said, and when & where you said it. It is good to know you leave your statements open to interpretation.

Posted: Mon, 15 Sep 2014 13:44:18 -0500 Message ID: <8738bs2076.fld@barrow.com>

Wherein you stated the following:

âEURoeA non-destructive workflow means you can *undo* and then *redo*.

That is not a reversible function.

And that is true!

For example, you can add sharpening with a high pass sharpen tool to an image, save it as a JPEG, send it to someone else, and they can use a blur tool to reverse the sharpen.

If the sharpening is done with UnsharpMask that cannot be done. USM is not reversible.âEUR

And that is true!

Eric Stevens
I understood him to be saying that inspite of the losses of a JPEG conversion, recovery of the original sharpness is possible if the original sharpening process used a high pass filter. That while saving as a JPEG will always cause losses, this will not prevent a Gaussian blur operation from recovering the sharpness of the original image.

Floyd L. Davidson
Again, that is extremely close but lets not suggest that the "sharpness of the original image" is *fully* recovered. In other words "sharpness of the original image" is not the same as "original sharpness".

Savageduck
So, it isnâEUR(Tm)t a fully reversible and/or non-destructive process?

I've never claimed it was in any way a "non-destructive process".

Reversible does not necessarily mean revertable from one specific state to another specific previous state. It means incremental variation is incrementally reversed. How far it can be taken is another matter.

Floyd L. Davidson
Regardless, none of that is what I said.

Savageduck
I know, this is what you said:

âEURoeFor example, you can add sharpening with a high pass sharpen tool to an image, save it as a JPEG, send it to someone else, and they can use a blur tool to reverse the sharpen.âEUR

And that includes none of the garbage you've added to make your strawman weak enough that even you can try hitting.

Of course winning a battle with a strawman just makes you a meaningless waste of time.

Regardless of what you understood him to mean, what did he actually say? I doubt that Floyd would be please with anybody being so bold as to paraphrase his words. He does mean what he says doesnâEUR(Tm)t he?

Floyd L. Davidson
So why do you insist on making absurd claims suggesting the meaning is other than precisely what is stated! Your argument on this is a total fabrication on your part. It's dishonest and lacks integrity.

Savageduck
No. I fully give you credit for what you said, and that you meant every word.

And we will give you credit for all the straw *you* added.

I certainly donâEUR(Tm)t have the engineering background you and Floyd have, but I have a solid education in the sciences

Floyd L. Davidson
Solid as a pile of sand?

Savageduck
There goes Floyd again, demeaning wherever he can. Four years at Syracuse is âEURoesolid as a pile of sandâEUR, interesting.

You've demonstrated that even a fine school such as Syracuse cannot instill common sense or wisdom into some people.

Your "solid" education isn't.

and I have had years of experience in microbiology and lab work, all of which strangely led me down another career path solidly entrenched in investigation. One of the things I have been quite good at over the last 30+ years is remembering and pinning down inconstancies in statements. They can be revealing. So rather than put words in his mouth, let Floyd's words stand on their own without your interpretation.

Floyd L. Davidson
As every criminal trial attorney is aware, a typical police officer is very good at twisting words to insinuate guilt where none exists. You *create* the "inconstancies" to pin down.

Savageduck
Just the facts as they reveal themselves, and those are presented to the D.A. to twist and insinuate guilt. I was actually quite good at what I did.

No doubt. "Just the facts" is well known to mean clear distortion.

BTW: Nothing personal, but your Usenet client seems to have a problem with Unicode (UTF8) text encoding,

Nothing personal, but Usenet is an ascii text medium.

-- Floyd L. Davidson http://www.apaflo.com/ Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

Sandman (31m)
nospam (7h & 41m)