High-resolution image scaler using hierarchical motion estimation and overlapped block motion compensation

This paper presents a motion-compensated scaler to interpolate an arbitrary frame in a low resolution video sequence by using sparsely existing high resolution key frames. In order to minimize visually annoying blocking artifact caused by block motion compensation, hierarchical motion estimation is bi-directionally performed for forward and backward key frames. Also, bi-directional overlapped block motion compensation based on the predicted motion vectors is applied to the high resolution key frames. Simulation results show that the proposed algorithm provides significantly better subjective visual quality as well as higher PSNR than previous interpolation algorithms. The proposed algorithm can provide a differentiated functionality to cutting-edge digital cameras, camcorders, etc.