Subject | Re: Lenses and sharpening |
From | Savageduck |
Date | 09/18/2014 06:32 (09/17/2014 21:32) |
Message-ID | <2014091721321715897-savageduck1@REMOVESPAMmecom> |
Client | |
Newsgroups | rec.photo.digital |
Follows | Floyd L. Davidson |
Followups | Eric Stevens (4h & 31m) > Savageduck |
Floyd L. DavidsonFrom 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?
Savageduck <savageduck1@{REMOVESPAM}me.com>wrote:SavageduckFloyd L. Davidson
On 2014-09-18 01:00:46 +0000, Eric Stevens <eric.stevens@sum.co.nz>said:Eric StevensSavageduck
On Wed, 17 Sep 2014 06:05:14 -0700, Savageduck <savageduck1@{REMOVESPAM}me.com>wrote:SavageduckEric Stevens
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:
--- snip ---Eric StevensSavageduckSavageduckEric Stevens
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.
That's why I never included a conversion to JPG in my example of a reversible process.
Â...but that genius Floyd did.
--- snip ---Eric StevensNo 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.
I've had a look and I cant see where. Could you refer me to the message?
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.âEURÂ
Note, the words, âEURoesave it as a JPEG,âEURÂ.
As I said, that genius Floyd did.
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.