I don't have any sources, But I've heard several claims that a photo can be edited in such a way that there is literally no trace it was digitally edited.
My question regards the usual digital photo, also I'm not asking about photoshop specifically but on any software tool.
[The motivation to my question is if this claim is correct then any digital image won't hold as evidence in court.]
From this motivation, one can draw in what sense "edit a photo" stands.
Is this claim correct correct? To what extent is this true?
[I will try to investigate where I've read this claim, but I'm not so sure I will find it]
EDIT: I see my question arises several ambiguities (which probably stems from my lack of understanding in this subject), I will address the subject of which editing I refer to.
In particular let me give some examples: planting people in photos, changing facial features of people, removing objects, modifying features of objects.
I know those examples are broad but I ask you to address those examples in the "intuitive" way, not in a general way.
I will edit this question to be more appealing, once I will see it addresses main concerns.