It's been established that "how do I do this with photoshop" Questions are Ok so long as they pertain to particular photographic goal.
It's also been established that Photo Editing, Manipulation, and Image processing are unique domains (or unique solutions to a problem.) and that any of those domains might be on topic here. Again it was hinted at in the
Finally, it appears that programming questions are not necessarily off topic so long as the question and correct answer pertain to photographic principles rather than programmatic issues
Where I still would like to see a bit of clarification is around image processing methods. For example, in This question the OP has already photographically assessed the imagery and wants to know how handle the telemetry programmatically. I have an answer for him that involved Machine Learning but it doesn't really seem like a photographic answer... If none of us can think of a photographic answer does that make the question off topic? He is asking about working with images just in more of a statistical sense. Not to be too esoteric here but images are just a particular type of data array so it's hard to know where data analysis questions become off topic.
Further food for thought, I just answered this question on CS SE and don't think it would have been considered to be on topic here. Does the fact that the CS question dealt with an non-pictorial subject somehow change the salience?
Sorry if this question is too nebulous. I'm happy to refine it based on suggestions