Judge by/from

Hello all!

Hope, you'll help me with this tiny question: what's the difference between "judge from" and "judge by"?

As I (seem to) understand, "from" is used mostly to refer to a source of information and "by" — to an item that it itself the subbject of investigation:

"Judging from what you said"
"Judging by your accent"

But I am not sure.

I don't think there is any difference, but I could be wrong... Either one sounds okay to me in both of those phrases.

Ok, thanks.