On 2014-09-16 02:07:14 +0000, (Floyd L. Davidson) said:

Savageduck wrote:
On 2014-09-15 22:33:57 +0000, Eric Stevens said:

On Mon, 15 Sep 2014 10:15:37 -0700, Savageduck
wrote:

On 2014-09-15 16:39:45 +0000, (Floyd L. Davidson) said:

nospam wrote:
In article , Floyd L. Davidson
wrote:

UnSharpMask is not reversible.
it is with a non-destructive workflow.
I'm sorry that you don't understand the meaning of
that.
I know your feelings regarding Photoshop, but using
Adobe's *Smart
Object* concept provides a different level of non-destructive workflow.
Creating a new adjustment layer and converting it to a *Smart Object*
gives one the ability to apply any filter, including USM and any of the
other sharpening tools or filters to that *Smart Object*.
If the particular adjustment results are not to one's liking, then
double clicking on that filter in the *Smart Object* layer will reopen
the filter dialog to allow changes to the filter parameters.
In the case shown below I have applied USM to a *Smart Object* and I
can return to it as often as I want to adjust the USM parameters, all
non-destructively.
https://dl.dropbox.com/u/1295663/FileChute/screenshot_900.jpg
All adjustments made to *Smart Objects*, in Photoshop
terms, are
non-destructive.
I fully expect you to tell me I am wrong.
I will tell you that you are discussing a point which
is not the point
raised by Floyd. So too is nospam, but that is not surprising.
Floyd was referring to a reversible function: run it
forwards and you
get sharpening; run it backwards and you get blur. Or the other way
around if you wish.

I got what Floyd was talking about when he was talking
of high pass sharpening, and reversing it by applying
the corresponding reverse parameter blur. However, he
also stated above, "UnSharpMask is not reversible". My
point addressed the fact that for some of us, that is
not an entirely valid statement.

That is in fact a valid statement. The USM function is
not reversible.

Note: my words were; “not entirely valid”. Meaning there is certainly
an element of validity to your statement, because apparently (I don’t
know this for sure) you don’t use a non-destructive workflow.

That isn't a opinion, it's a fact.

It is certainly a fact in a world where you have taken that step to
merge layers and compress the file into a lossy JPEG now locked in
stone. From that point on, you are correct, it is not reversible.

However, in the non-destructive workflow I use it is quite possible for
me to return to my layered PSD or TIF (I might well have a JPEG of the
adjusted image saved somewhere for sharing) and I can return to reopen
each filter, or adjustment layer, including USM, make tweaks to the
parameters, or even remove that USM layer altogether. That will give me
something quite different. The JPEG which might be produced is just a
compressed, lossy snapshot of the actual, non-destructively adjusted,
and uncompressed layered PSD, or TIF.


--
Regards,

Savageduck