Edge may still be fine, given the oxidation as shown, although I agree with Euclid that viewing it under a decent achromatic loupe (~10x) would help determine this. If the blade was stored away dampened, and that is the culprit, then from now on it is important first to rinse the blade completely, then wick off the excess moisture with a towel or tissue, and then strop the blade afterwards, around 5-10 laps on cotton (to further dry the bevel and edge) and then 30-40 laps leather. And as far as stropping goes, that may be all one needs. Leave out opened to dry completely before storing it away.