Yes, your comma usage there is correct. The comma sets off the clause specifying the conditional, making the meaning explicit and matching the way that we'd say the sentence (a comma is voiced as a brief pause). Without the comma, it might appear to be a predicate construction stating the use was performing the act of providing.
High enough resolution is also correct. Resolution high enough is perfectly valid as well, but it requires a determiner of some sort for resolution; most likely the article a.