In tracking face and facial actions of unknown people, it is essential to take into account two components of facial shape variations: shape variation between people and variation caused by different facial actions such as facial expressions. This paper presents a monocular method of tracking faces and facial actions using a multilinear face model that treats interpersonal and intrapersonal sha...

This paper examines the potential benefits of applying next best view planning to sequential 3D reconstruction from unordered image sequences. A standard sequential structure-and-motion pipeline is extended with active selection of the order in which cameras are resectioned. To this end, approximate covariance propagation is implemented throughout the system, providing running estimates of the ...

We present several methods for the estimation of relative pose between planes and cameras, based on projections of sets of coplanar features in images. While such methods exist for simple cases, especially one plane seen in one or several views, the aim of this paper is to propose solutions for multi-plane multi-view situations, possibly with little overlap. We propose a factorization-based met...

We study 3D retinal surface reconstruction by using an affine camera due to two following reasons: (1) NIH’s retinal imaging protocols specify a narrow field of view and (2) each retinal image has small depth variation. Specifically, we incorporate the prior knowledge of human retina geometry in the reconstruction process, and introduce a pointbased approach to estimate the retinal spherical su...

ABSTRACT Architectural documentation is carried out mostly with (analogue or digital) non-metric cameras or video-cameras. Unknown internal geometry is a main problem in this context, particularly for wide-angle lenses with their considerable amount of distortion. Self-calibrating bundle adjustment or 3D test-field calibration may provide straightforward answers to this problem, yet on occasion...

Wiberg matrix factorization breaks a matrix Y into low-rank factors U and V by solving for V in closed form given U , linearizing V (U) about U , and iteratively minimizing ||Y − UV (U)||2 with respect to U only. This approach factors the matrix while effectively removing V from the minimization. We generalize the Wiberg approach beyond factorization to minimize an arbitrary function that is no...

We present a scheme for incorporating scene constraints into the auto-calibration process for the structure and motion recovery problem. The steps covered by the scheme include projective factorization of the joint image measurement matrix, recovery of the absolute dual quadric, the upgrade from projective structure to its Euclidean counterpart, and incorporation of constraints from orthogonal ...

We present a supervised approach to recover 3D models of buildings from multiple uncalibrated views. With this method the user matches 3D vertices in the images and defines the 3D model of the building with the help of elementary and intuitive geometric constraints. At the same time, a graph describing relationships between vertices is built. Then, unknown parameters of this graph are estimated...

Camera calibration has always been an essential component of photogrammetric measurement. Nowadays, with self-calibration being an integral and routinely applied operation within photogrammetric triangulation, especially in high-accuracy close-range measurement. Photogrammetric camera calibration is usually carried out together with the calculation of object coordinates such as principal distan...

Bundle Adjustment is a key process to enhance the global accuracy of the 3D camera pose and structure estimation in the framework of structure from motion over long video sequences. However, most bundle adjustment algorithms require sufficient visual feature correspondences from each camera frame to its neighboring frames in video sequences, which are hard to collect in real environments, espec...