Halliday & Matthiessen (2014: 379):
When functioning as Epithet, these forms usually have the sense of the finite tense to which they are most closely related: the present participle means ‘which is (was/will be) ... ing’, the past participle means ‘which has (had/will have) been ... ed’. When functioning as Classifier, they typically have the sense of a simple present, active or passive: present (= active) ‘which ... s’, past (= passive) ‘which is ... ed’.
If however the verb is one which does not normally take the ‘present in present’ tense be ... ing (i.e. a verb expressing a mental or relational process), the distinction between ‘which ... s’ and ‘which is ... ing’ is neutralised;