This document discusses optimizing content-based image retrieval in peer-to-peer systems. It summarizes previous work on content-based image retrieval using multi-instance queries in peer-to-peer networks. The authors propose two optimizations to previous work: 1) clustering peers to reduce search time, and 2) constructing a search index at cluster heads to avoid searching each peer. Their experiments show the proposed approach reduces search time compared to previous work, with some reduction in accuracy that improves as more nodes are added. The authors plan future work to analyze performance with different cluster sizes and representations for faster search.