Citation

Xu W, Yin S, Liu L, Liu Z, Wei S. Sensors (Basel) 2015; 15(8): 20752-20778.

Affiliation

Institute of Microelectronics, Tsinghua University, Beijing 100084, China. wsj@tsinghua.edu.cn.

Copyright

(Copyright © 2015, MDPI: Multidisciplinary Digital Publishing Institute)

DOI

10.3390/s150820752

PMID

26307996

Abstract

It is important to reduce the time cost of video compression for image sensors in video sensor network. Motion estimation (ME) is the most time-consuming part in video compression. Previous work on ME exploited intra-frame data reuse in a reference frame to improve the time efficiency but neglected inter-frame data reuse. We propose a novel inter-frame data reuse scheme which can exploit both intra-frame and inter-frame data reuse for ME in video compression (VC-ME). Pixels of reconstructed frames are kept on-chip until they are used by the next current frame to avoid off-chip memory access. On-chip buffers with smart schedules of data access are designed to perform the new data reuse scheme. Three levels of the proposed inter-frame data reuse scheme are presented and analyzed. They give different choices with tradeoff between off-chip bandwidth requirement and on-chip memory size. All three levels have better data reuse efficiency than their intra-frame counterparts, so off-chip memory traffic is reduced effectively. Comparing the new inter-frame data reuse scheme with the traditional intra-frame data reuse scheme, the memory traffic can be reduced by 50% for VC-ME.

Language: en