Semantics question

[tomczak]

A vertical series of transformations could be called a branch. If there is a splitter in it that will create a side branch (and that may be appropriate since the branches are calculated from left to right, as I understand it, so the main/left branch first, then side branches to the right of it in turn).

But then how to call a new series of transformations starting from File Open, Paste or Copy? A new stream? A new branch?

Then each transformation within a stream or a branch has an input and output image. The preview of a current transformation shows an output image if the transformation control is closed. But when its open it could show input image, or output or both. Which entity should I call an image and which a transformation (as in a set of processing instructions which sit in a 'widget' (that's from PWP7) that displays thumbnail of this transformation output image?).

All in all it doesn't make much difference, but I keep scratching my head every time I'm trying to describe something and can't find the right words.

[jsachs]

I use the term branch to apply to any connected set of transformations.

I use the term side-branch to refer to the branches under a splitter.

I use the term top-level transformation to refer to the topmost transformation of a branch.

I tend to use the terms image and transformation interchangeably, although to be more accurate image refers to the image data while transformation refers to the set of instructions that generates the image. The difference is important in some contexts such as when copying since what is being copied is the transformation and not the image.

Incidentally, branches are not always calculated left to right -- it depends on the dependency relationships as everything a transformation depends on must the calculated before the transformation can be calculated.

[tomczak]

Thanks. So for instance, if I refer to creating a 'new branch' (as opposed to new side branch) this will be universally understood as a new series of connected transformations with a new top-level transformation. i.e. describing it as stream to differentiate it from side branches is unnecessary?

Similarly, all branches under the splitter are 'side branches' without any main branch?

[jsachs]

As you have probably realized by now, I am making this up as I go along, but I would call a "new branch" as you are calling it a "new top-level branch", and I would consider a side-branch also to be a branch.

I use the terms upstream and downstream to refer to the ordering based on dependency. Upstream transformations are one a transformation depends on and downstream transformations are those that depend on it.