Adaptive encoding of zoomable video streams based on user access pattern

Abstract

Zoomable video allows users to selectively zoom and pan into regions of interest within the video for viewing at higher resolutions. Such interaction requires dynamic cropping of RoIs on the source video. In this paper, we consider how the bandwidth needed to transmit the RoIs can be reduced by carefully encoding the source video. The key idea is to exploit user access patterns to the RoIs, and encode different regions of the video with different encoding parameters based on the popularity of the region. We show that our encoding method can reduce the expected bandwidth by up to 27%. Copyright 2010 ACM.