Microsoft Research Blog

Artificial intelligence

  1. Spline-Based Image Registration 

    March 30, 1997 | Rick Szeliski and James Coughlan

    The problem of image registration subsumes a number of problems and techniques in multiframe image analysis, including the computation of optic flow (general pixel-based motion), stereo correspondence, structure from motion, and feature tracking. We present a new registration algorithm based on spline representations of the…

  2. Identifying Topics by Position 

    March 1, 1997 | Chin-Yew Lin and Eduard Hovy

    This paper addresses the problem of identifying likely topics of texts by their position in the text. It describes the automated training and evaluation of an Optimal Position Policy, a method of locating the likely positions of topic-bearing sentences based on genre-specific regularities of discourse…

  3. Motion estimation with quadtree splines 

    November 30, 1996 | Rick Szeliski and Harry Shum

    This paper presents a motion estimation algorithm based on a new multiresolution representation, the quadtree spline. This representation describes the motion field as a collection of smoothly connected patches of varying size, where the patch size is automatically adapted to the complexity of the underlying…

  4. Stereo matching with non-linear diffusion 

    June 17, 1996 | Daniel Scharstein and Rick Szeliski

    One of the central problems in stereo matching (and other image registration tasks) is the selection of optimal window sizes for comparing image regions. This paper addresses this problem with some novel algorithms based on iteratively diffusing support at different disparity hypotheses, and locally controlling…

  5. An Integrated Neural and Algorithmic System for Optical Flow Computation 

    May 1, 1996 | Antonio Criminisi, G. A. M. Gioiello, D. Molinelli, and F. Sorbello

    Motion detection plays a central role in several visual environments: knowledge of object velocities and trajectories is fundamental in scene interpretation and segmentation. This task appears a simple problem, but detecting moving objects is very difficult, in fact this is a problem that cannot be…

  6. Image mosaicing for tele-reality applications 

    December 4, 1994 | Rick Szeliski

    This paper presents some techniques for automatically deriving realistic 2-D scenes and 3-D geometric models from video sequences. These techniques can be used to build environments and 3-D models for virtual reality application based on recreating a true scene, i.e., tele-reality applications. The fundamental technique…

  7. Toward an assembly plan from observation. I. Task recognition with polyhedral objects 

    May 31, 1994 | Katsushi Ikeuchi and T. Suehiro

    The authors present the assembly-plan-from-observation (APO) method for robot programming. The APO method aims to build a system that has the capability of observing a human performing an assembly task, understanding the task based on the observation, and subsequently generating a robot program to achieve…

  8. Efficient quadtree coding of images and video 

    April 30, 1994 | Gary J. Sullivan and R.L. Baker

    The quadtree data structure is commonly used in image coding to decompose an image into separate spatial regions to adaptively identify the type of quantizer used in various regions of an image. The authors describe the theory needed to construct quadtree data structures that optimally…

  9. Surface reflection: physical and geometrical perspectives 

    June 30, 1991 | S.K. Nayar, Katsushi Ikeuchi, and T. Kanade

    Reflectance models based on physical optics and geometrical optics are studied. Specifically, the authors consider the Beckmann-Spizzichino (physical optics) model and the Torrance-Sparrow (geometrical optics) model. These two models were chosen because they have been reported to fit experimental data well. Each model is described…