A Hybrid Quantum Encoding Algorithm of Vector Quantization for Image   Compression
  Many classical encoding algorithms of Vector Quantization (VQ) of image compression that can obtain global optimal solution have computational complexity O(N). A pure quantum VQ encoding algorithm with probability of success near 100% has been proposed, that performs operations 45sqrt(N) times approximately. In this paper, a hybrid quantum VQ encoding algorithm between classical method and quantum algorithm is presented. The number of its operations is less than sqrt(N) for most images, and it is more efficient than the pure quantum algorithm.   Key Words: Vector Quantization, Grover's Algorithm, Image Compression, Quantum Algorithm 
Chao-Yang Pang, Zheng-Wei Zhou, and Guang-Can Guo