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:

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

Savageduck
So? The fact still remains, regardless of personal opinion about Adobe, Lightroom, & Photoshop, those using that software have the ability to maintain a fully non-destructive, and reversible workflow, that includes reversing the effects of any filter including USM.

Floyd L. Davidson
It's not a "reversible" workflow. The correct terms would be either a non-linear undo, or simply that it can be reverted.

Savageduck
I guess you are in complete denial with regard to the capabilities of current versions of Lightroom & Photoshop, so it doesn?t really matter what you want the correct terms would be. I will take ?reversible? out of my obviously too hyperbolic for you, description of the capabilities of those Adobe products, and just continue to use the word Adobe uses, ?non-destructive?.

âEUR¦and if you are going to start that reverse mathematical operation from a compressed, & lossy JPEG, good luck getting back to where you started.

Floyd L. Davidson
Your workflow, even if non-destructive, will be totally unable to deal with reverting any previous editing with the exception of processes, such as sharpen (not USM), that are reversible.

Savageduck
It seems that you have never worked with a truly non-destructive workflow, with Photoshop and Lightroom I have a totally reversible workflow which can deal with reverting crops, spot removal, content aware fill, content aware move, any of the various grad filters available, and filters, including the notorious USM.

Eric Stevens
The reason that all this argument is underway is that you and nospam fail to recognise that a "totally reversible work flow" is one thing but a reversible process is another. What Floyd has been saying is that sharpening with a high-pass filter is basically the same as Gaussian blur except that one goes forward and the other goes backwards. Whatever you do with one can be undone with the other.

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.

This is not the same as just cancelling the operation as you do when you delete it from a sidecar file.

Savageduck
We have an apples & oranges issue here I have been speaking of the two varieties of non-destructive workflow available to PS and LR users, they are not the same. What you have said above is sort of correct for Lightroom, but not for Photoshop where there are no sidecar, or catalog files. you should learn the difference.

As I have said in some other responses of mine, the JPEG which might be produced is just a compressed, lossy snapshot of the actual, non-destructively adjusted, and uncompressed layered PSD, or TIF. It is best to consider it a version, and there is no point in even trying to rework it. Call it ?version-1.jpg?. Once you are done with readjusting the layered PSD/TIF you can produce ?version-2.jpg?, and still have the ability to return to the working PSD/TIF to produce a ?version-3.jpg?.

The product of a non-destructive workflow is not a JPEG, and there is little point in doing any reversion work in those JPEGs other than some polishing tweaks.

Obviously there is nothing I can say or demonstrate to convince you that I am able to do what I say I can with LR &/or PS. You are stuck in a World void of Adobe where you spin your knowledge of fundamental technical minutia into a shield of denial. I will not be, nor do I strive to be the the technical wizard you obviously are, but this is one of those times where you have not moved with the times.

As I said when I first came into this thread, I fully expected you to tell me I was wrong and an ignoramus (which I might well be regarding some stuff), and you met that expectation, and there isn?t much point in going any further and we should just agree to disagree, you in your World, and me in mine.

Eric Stevens
You could always try to understand what he (and I) are really saying. It's not what you seem to think it is.

Savageduck
What you claim isnÂ’t actually 100% possible once you are trying to reverse changes to a JPEG. It might look close, but an exact reversal, never. However, I can make that exact reversal using the tools I (& you) have available in Photoshop.

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