Partitional k-means clustering based hybrid DCT-Vector Quantization for image compression

In this paper, we propose Hybrid DCT-VQ, a lossy image compression technique based on Vector Quantization (VQ). In the proposed technique, we use the concept of energy compaction property of DCT to reduce the computational cost of codebook and to speed up the VQ process. This method is tested on set of standard test images for different sub-block sizes. The experimental simulation results infer some interesting outcomes in terms of execution time and compression ratio as compared to that of conventional VQ process.