Savageduck
On 2014-09-18 04:17:59 +0000, floyd@apaflo.com (Floyd L. Davidson) said:

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

Savageduck
On 2014-09-18 01:00:46 +0000, Eric Stevens <eric.stevens@sum.co.nz>said:

Eric Stevens
On Wed, 17 Sep 2014 06:05:14 -0700, Savageduck <savageduck1@{REMOVESPAM}me.com>wrote:

Savageduck
On 2014-09-17 09:22:00 +0000, Eric Stevens <eric.stevens@sum.co.nz>said:

Eric Stevens
On Tue, 16 Sep 2014 22:27:43 -0700, Savageduck <savageduck1@{REMOVESPAM}me.com>wrote:

Savageduck
On 2014-09-17 04:08:19 +0000, Eric Stevens <eric.stevens@sum.co.nz>said:

Eric Stevens
On Tue, 16 Sep 2014 07:53:15 -0700, Savageduck <savageduck1@{REMOVESPAM}me.com>wrote:

Savageduck
On 2014-09-16 10:36:29 +0000, floyd@apaflo.com (Floyd L. Davidson) said:

Eric Stevens
--- snip ---

Savageduck
The reverse process performed on a lossy, compressed JPEG is not going to reverse the HPF to return to the original state. That was lost once the save was executed.

Eric Stevens
That's why I never included a conversion to JPG in my example of a reversible process.

Savageduck
Â...but that genius Floyd did.

Eric Stevens
--- snip ---

No one who understood what we were trying to talk about would claim that a JPG conversion is a reversible process.

Savageduck
Â...but that genius Floyd did.

Eric Stevens
I've had a look and I cant see where. Could you refer me to the message?

Savageduck
With pleasure.

That wasnâEUR(Tm)t too tough to find: Posted: Mon, 15 Sep 2014 13:44:18 -0500 Message ID: <8738bs2076.fld@barrow.com>

Wherein Floyd stated the following:

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

That is not a reversible function.

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?

Note, the words, âEURoesave it as a JPEG,âEUR?.

As I said, that genius Floyd did.

Floyd L. Davidson
So we now we know you can't read.

What I said was that *high pass sharpen is reversible*. It is, even if a few people are unable to either understand or accept that it is.

Savageduck
From a lossy, compressed JPEG? You did say “save it as a JPEG” didn’t you? Have you also developed the mathematics to reverse the compression and loss in that High-Pass sharpened file, so that you can return it to its original state?

HPS might well be reversible, but returning the file to its truly original state after being saved as a JPEG is improbable.

However, I have the tools to do that, with HSP, and even USM regardless of how much you stamp your feet and say I can’t.