Camera motion estimation through planar deformation determination

TL;DR

This paper introduces a fast, robust global method for estimating camera motion from video sequences by modeling planar deformation with quadratic approximation, assuming scene depth constancy and small variations.

Contribution

It presents a novel quadratic deformation model that separates similarity and projective components, enabling direct estimation of camera motion parameters.

Findings

Method is fast and robust for adjacent frames

Quadratic approximation yields accurate motion estimation under certain conditions

Separation of deformation components improves estimation accuracy

Abstract

In this paper, we propose a global method for estimating the motion of a camera which films a static scene. Our approach is direct, fast and robust, and deals with adjacent frames of a sequence. It is based on a quadratic approximation of the deformation between two images, in the case of a scene with constant depth in the camera coordinate system. This condition is very restrictive but we show that provided translation and depth inverse variations are small enough, the error on optical flow involved by the approximation of depths by a constant is small. In this context, we propose a new model of camera motion, that allows to separate the image deformation in a similarity and a ``purely'' projective application, due to change of optical axis direction. This model leads to a quadratic approximation of image deformation that we estimate with an M-estimator; we can immediatly deduce camera motion parameters.