My last word on color spaces

Hi Everybody,
Here's my last word on the number of documents and my search for the missing working space.
Semantics is the reason for the confusion.  It is confusing to the user but should not be confusing to color management people (except for the resident expert).
Consider the following two images.



As a user of PhotoPaint, I would consider them to be the same image.  The source is exactly the same image from the camera.  The one on the left is right out of the camera.  The one on the right looks like it has been modified.  But so what.  It certainly looks to the user like the program has not created two images in RAM.  It looks like the program has simply changed the image in the code so it now looks like the one on the right.

But that's not what the programmer, Adobe, Fraser et all, and color management gurus will say.  The one on the right was ordered by me by using the document color management dialog.  I asked it to assume (not change) the embedded profile.  In order to get there, the programmer must use two profiles to make the conversion on a pixel by pixel basis plus interpolation of both profiles.  As the work progresses, the image on the right ends up as a separate image in memory.

For convenience, one can give the two images in memory different names -- say document 1 and document 2.  In other cases, one could say that the image on the left is in document space and the one on the right is in Working Space.  They are just names used to show that the two images in memory are in different color spaces.  But only one is displayed on the monitor.

The programmer could also destroy the first image to save space in memory.  That seems to be happening when you switch spaces by using the menu.  However at least one must be kept.  By convention, it's called the Working Space in Adobe - the central space in CDGS - the intermediate space in Fraser et all - etc.

So the user sees one document. 
Color management sees two. 
The programmer sees as many as have not been destroyed.

Phil