Representing Moving Images with Layers
John Y. A. Wang and Edward H. Adelson
IEEE Transactions on Image Processing, 3(5):625-638 (1994).
We describe a system for representing moving images with sets of overlapping layers. Each layer contains an intensity
map that definges the additive values of each pixel, along with an alpha map that serves as a mask indicating the
transparency. The layers are ordered in depth and they occlude each other in accord with the rules of compositing.
Velocity maps define how the layers are to be warped over time. The layered representation is more flexible than
standard image transforms and can capture many important properties of natural image sequences. We describe some
methods for decomposing image sequences into layers using motion analysis, and we discuss how the representation may
be used for image coding and other applications.