Title: "Mosaicing with Parallax using Time Warping".

Authors
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Alex Rav-Acha, Yael Shor, Shmuel Peleg

Affiliations
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Alex Rav-Acha & Shmuel Peleg:
	School of Computer Science and Engineering
	The Hebrew University of Jerusalem
	91904 Jerusalem, Israel
Yael Shor:
	Humaneyes Technologies Ltd.

E-Mail
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{alexis,yaelshor,peleg}@cs.huji.ac.il

Abstract
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2D image alignment methods are applied successfully for mosaicing aerial
images, but fail when the camera moves in a 3D scene. Such methods can not
handle 3D parallax, resulting in distorted mosaicing. General ego-motion
methods are slow, and do not have the robustness of 2D alignment methods.

We propose to use the {\it x-y-t} space-time volume as a
tool for depth invariant mosaicing. When the camera moves on a straight
line in the $x$ direction, a {\it y-t} slice of the space-time volume is a
panoramic mosaic, while a {\it x-t} slice is an EPI plane.
{\it Time warping}, which is a resampling of the {\it t} axis,
is used to form straight feature lines in the EPI planes. This
process will simultaneously give best panoramic mosaic in the {\it
y-t} slices.

This approach is as robust as 2D alignment methods, while giving depth
invariant motion (``ego motion''). Extensions for two dimensional
camera motion on a plane are also described, with applications for 2D
mosaicing, and for image based rendering such as ``light field''.

Link
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 http://www.cs.huji.ac.il/~alexis/ivr04/