Learning to Hash for Big Data 李武军 LAMDA Group 南京大学计算机科学与技术系 软件新技术国家重点实验室 liwujun@nju.edu.cn May09,2015 日卡三4元，互Q0 Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA,CS.NJU 1/43
Learning to Hash for Big Data o… LAMDA Group HÆåÆOéÅâÆÜE‚X ^á#E‚I[:¢ø liwujun@nju.edu.cn May 09, 2015 Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA, CS, NJU 1 / 43
Outline ① Introduction o Problem Definition oExisting Methods 2Scalable Graph Hashing with Feature Transformation Motivation ●Model and Learning o Experiment Conclusion ④ Reference 日卡回”三4元，互Q0 Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA,CS.NJU 2/43
Outline 1 Introduction Problem Definition Existing Methods 2 Scalable Graph Hashing with Feature Transformation Motivation Model and Learning Experiment 3 Conclusion 4 Reference Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA, CS, NJU 2 / 43
Introduction Outline ① Introduction o Problem Definition oExisting Methods Scalable Graph Hashing with Feature Transformation o Motivation Model and Learning o Experiment Conclusion Reference +日卡+得￥三4元互)Q0 Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA,CS.NJU 3 /43
Introduction Outline 1 Introduction Problem Definition Existing Methods 2 Scalable Graph Hashing with Feature Transformation Motivation Model and Learning Experiment 3 Conclusion 4 Reference Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA, CS, NJU 3 / 43
Introduction Problem Definition Nearest Neighbor Search(Retrieval) oGiven a query point g,return the points closest(similar)to g in the database (e.g.,images). o Underlying many machine learning,data mining,information retrieval problems Challenge in Big Data Applications: o Curse of dimensionality Storage cost ●Query speed 日卡三4元，互Q0 Li (http://cs.nju.edu.cn/lvj) Learning to Hash LAMDA,CS.NJU 4/43
Introduction Problem Definition Nearest Neighbor Search (Retrieval) Given a query point q, return the points closest (similar) to q in the database (e.g., images). Underlying many machine learning, data mining, information retrieval problems Challenge in Big Data Applications: Curse of dimensionality Storage cost Query speed Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA, CS, NJU 4 / 43
Introduction Problem Definition Similarity Preserving Hashing h(Statue of Liberty)= h(Napoleon)= h (Napoleon)= 10001010 01100001 011001Q1 flipped bit Should be very different Should be similar 0Q0 Li (http://cs.nju.edu.cn/lvj) Learning to Hash LAMDA.CS.NJU 5/43
Introduction Problem Definition Similarity Preserving Hashing Li (http://cs.nju.edu.cn/lwj) Learning to Hash LAMDA, CS, NJU 5 / 43