Im working on image clustering (finding duplicates). I have a metric for images, it uses histogram features (mean, dispersion, skewnewss) for each color channel. So there are 9 dimensions. It is quite easy to calculate distance between two images (L1), but I don't know how to cluster them. Is there any clustering algorithms that use only the metric, other than bruteforce? Wikipedia article tells about projected clustering, how can it be implemented?