Scalable fusion using a 3D dual tree wavelet transform

This paper introduces a novel system that is able to fuse two or more sets of multimodal videos in the compressed domain. This is achieved without drift and produces an embedded bitstream that offers fine grain scalability. Previous attempts to fuse in the compressed video domain have been not been possible due to the complications of predictive loops within standard video encoding techniques. The compression system is based on an optimised spatio-temporal codec using the 3D Discrete Dual-tree Wavelet Trans- form (DDWT) together with bit plane encoding method SPIHT and a coefficient sparsification process (noise shaping). Together, these methods are able to efficiently encode a video sequence without the need for motion compensation due to the directional (in space and time) selectivity of the transform. This enables scalable compressed domain fusion without drift. This results in extremely flexible fusion scenarios in dynamic bandwidth environments where there are variable client receiving capabilities.