The Journey to Optimizing Billion-scale Image Search (1/2)

This post details the first-generation image search system built by Yupoo Picture Manager, which used the pHash algorithm for feature extraction and Elasticsearch for similarity calculation based on Hamming distance. It explains the limitations of pHash, particularly its inability to handle image integrity destruction, and sets the stage for a second-generation system that would likely employ more advanced vector embedding techniques for billion-scale image search.