how to determine a balanced or perfectly balanced Binary search tree ( just from the picture )

I am not sure how to determine if a tree is balanced, perfectly balanced, or neither if I have it as a picture not a code

For example if I have this tree How can I check if it's balanced, perfectly balanced, or unbalanced? and can someone give me an example of a perfectly balanced tree?

    [o]
   /   \
 [b]   [p]
   \    / \
  [d]  [m] [r]

Clearly I can tell that the tree is unbalanced if it was something like this:

      [b]
        \
        [d]
         \
          [r]
           \
           [c]

However, if it was something very similar to the one above I don't know how to get it

This is a perfectly balanced and balanced tree:

        [k]
       /   \
      [A]   [p]
            /  \
           [N]  [R]

Can someone please explain it to me?