[Gimp-user] non-destructive editing

[gimp_user]

On Thursday 27 September 2007 08:00:45 George Farris wrote:
> Though you object to selective discussion of your discorse, you have
> at least twice falsely referred to gimp's lack of a tool for "non-
> distructive editing".  The term is a contradiction in itself.  Perhaps
> you can take the time to explain your meaning?

Yes I do object to selective discussion because it means no one else is able 
to follow the whole thread when bits get cut out so the thread gets chopped 
into fragmnents - each one then gets followed selectively. Readers then find 
they have to flip backwards and forwards to follow the discussion.

As this was a diversion from an original topic in a separate thread, and 
because your question is such a good one,  I have decided to recast my 
original reply as a seperate topic and provide a little more detail.

This is not the first time a lack of understanding about the 
term "non-destructive editing" has come up and you are  not the only one who 
has the mistaken belief that it is OK to falsely accuse others on this list 
of something equivalent to having  
>"falsely referred to gimp's lack of a tool for "non- distructive editing"
when you do not even understand the term under discussion.  

I believe gimp is a "good enough" tool not to need inappropriate defensive 
reactions or ill-informed responses when its limitations are discussed. The 
discussion of limitations leads to enhancement and there his ample history of 
enhancement in Gimp's progress. Gimp is a substantial tool that, in common 
with all other tool sets has limitations and weaknesses. In non-destructive 
editing  Gimp's weaknesses are substantial, however once support for 16 bit 
per channel  AND native raw file handling has been developed the path will be 
open for solving the problem.

Before amplifying I do not want to you to have any mistaken impressions about   
photoshop because one of my irritations with PS is that it does not yet fully 
achieve fully non-destructive editing. Its support for non-destructive editing 
is now quite substantial. It is getting there by a process of incremental 
improvement (whilst gimp cannot approach it) and each 
version seems to provide me with a more complete set (e.g. I have just 
upgraded to CS3 which, among other things, now has exposure adjustments 
available as a 
non-destructive layer whereas in CS2 exposure was not accomplished 
non-destructively.) 

By this I mean that one starts with loading the original image and that 
original can remain in the bottom of the stack. In the case of professional 
digital images that means raw files are sourced and loaded as 16bit images.

Non-destructive editing can, for example, be accomplished by having each edit 
take place as a layer which can, at any later point, be revisited, either by 
by the original image manipulator or anyone further down the chain. That 
layer can therefore be tweaked later in the process.  There are some 
processes in PS that cannot be accomplished non-destructively but as Gimp 
does not even start with the ability to load a raw image or even an image at 
16 bit we cannot begin the process.

With non-destructive editing every individual edit can be selectively applied 
to the output (to screen, printer etc). Each edit is not applied to the 
original which remains intact. For example it means I could apply two 
alternative exposure corrections. At a very much later stage, and after much 
subsequent editing, either I or someone on some other machine, could print 4 
copies namely the original without either  correction, with the first 
correction only, the second correction, or the sum of both corrections.

Non-destructive editing also implies the ability to transfer files between 
people and organization in a form that they can amend the edits applied by 
previous manipulators.

This is not a complete answer because there is more to it but I hope I have 
geven enough information to help explain why non-destructive editing is not a 
contradiction and also to ask you to withdraw your rather unkind and 
inappropriate accusation of falsity.

Thanks