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

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
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.

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 isnâEUR(Tm)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.