nospam
In article <slrnm1m6c7.93o.mr@irc.sandman.net>, Sandman <mr@sandman.net>wrote:

Eric Stevens
What Floyd was saying was that High Pass Filter sharpening and Gaussian Blur are basically the same process and that process is fully reversible.

Sandman
All image effects in Photoshop are 100% reversible.

nospam
image effects in photoshop *can* be reversible, but they are not always because photoshop is at its core, a pixel editor. you have to take additional steps for something to be non-destructive.

Sandman
True - but the undo function in modern software is the perfect definition of a reversible process. It can reverse any effect done by anything in Photoshop.

nospam
undo only exists while you're using the app and it's within its undo history. at some point, it won't be undoable, generally when the file is saved but sometimes well before that, depending on the app. that's the whole problem with a traditional workflow.

with a non-destructive workflow, anything can be reversed at any time because the original data remains unaltered, including long after the app has been quit and even archived and later worked on with a different computer.

the difference is very important, and one which floyd and eric do not fully understand (or at all).

Sandman
That said, all image effects in Photoshop are fully reversible if the user chooses them to be, as you say. It's a choice, and if you want it, you can enable smart filters and have a fully reversible process.

It's great to have choices.

nospam
it is.