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James Diebel - Research Homepage | |
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Stanford University 353 Serra Mall Gates Building Room 116 Stanford, CA 94305-9010 |
E-mail: diebel stanford.eduPhone: (650) 725-8790 Fax: (650) 725-1449 |
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| Research |
| Resume |
| Personal |
This page contains details of my various current and past research projects. The first section below gives information regarding on-going research projects and links to unpublished reports and presentations. The second section has links to my published papers and presentations, as well as several movies, some taken from conference talks, some having only been used internally. Please email if you'd like permission to republish any of these results for comparison purposes.
Many of the videos require an after-market codec in order to to play
in Windows Media Player. For
a nice free Windows codec pack, check out
K-Lite Codec Pack, which seems to have just about everything you
need. The link I provided is to
free-codecs.com, which is
a great website. If you don't already have something like
this, you'll need it to view most of the videos on this page.
On-Going Research Projects
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VectorMagic: Bitmap to Vector Art Conversion (10/1/07) We have launched a new web service called VectorMagic (at vectormagic.stanford.edu) that performs automatic vectorization (i.e., auto-tracing). Vectorization (aka tracing) is the process of converting a pixel-based image (BMP, JPG, GIF, etc.) into an image represented by geometric shapes such as lines, circles and curves (EPS and SVG). The web service uses a Flash interface to provide an interactive environment in which to select the various configuration settings, issue the conversion job, and preview the results. |
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Trajectory Smoother (7/16/06) We have developed a piece of software for performing vehicle localization based on GPS, accelerometer, rate gyro, and wheel encoder measurements. This software performs a joint optimization over a large sliding window, leading to substantially better results than are possible with a Kalman-filter-based approach. A technical report on this project will be released here soon. The code, which is open source is available now at: |
Abstract— We present the three main mathematical constructs used to represent the attitude of a rigid body in three-dimensional space. These are (1) the rotation matrix, (2) a triple of Euler angles, and (3) the unit quaternion. To these we add a fourth, the rotation vector, which has many of the benefits of both Euler angles and quaternions, but neither the singularities of the former, nor the quadratic constraint of the latter. There are several other subsidiary representations, such as Cayley-Klein parameters and the axis-angle representation, whose relations to the three main representations are also described. Our exposition is catered to those who seek a thorough and unified reference on the whole subject; detailed derivations of some results are not presented. Keywords— Euler angles, quaternion, Euler-Rodrigues parameters, Cayley-Klein parameters, rotation matrix, direction cosine matrix, Cardan angles, Tait-Bryan angles, nautical angles, rotation vector, orientation, attitude, roll, pitch, yaw, bank, heading, spin, nutation, precession, Slerp
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Published Research Projects
My research projects are listed here in reverse chronological order. In all cases, please send data and code requests by email, stating your affiliation(s) and why you'd like access.
Abstract— This article describes the robot Stanley, which won the 2005 DARPA Grand Challenge. Stanley was developed for high-speed desert driving without human intervention. The robot's software system relied predominately on state-of-the-art AI technologies, such as machine learning and probabilistic reasoning. This article describes the major components of this architecture, and discusses the results of the Grand Challenge race. This paper
has been accepted for publication in the Journal of Field Robotics.
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Abstract— This paper presents a quantitative comparison of several multi-view stereo reconstruction algorithms. Until now, the lack of suitable calibrated multi-view image datasets with known ground truth (3D shape models) has prevented such direct comparisons. In this paper, we first survey multi-view stereo algorithms and compare them qualitatively using a taxonomy that differentiates their key properties. We then describe our process for acquiring and calibrating multiview image datasets with high-accuracy ground truth and introduce our evaluation methodology. Finally, we present the results of our quantitative comparison of state-of-the-art multi-view stereo reconstruction algorithms on six benchmark datasets. The datasets, evaluation details, and instructions for submitting new models are available online at Multi-View Stereo Evaluation Homepage. This paper was presented at the
IEEE Computer Society Conference on Computer Vision and Pattern
Recognition (CVPR06) in June, 2006.
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Abstract— This paper describes a highly successful application of MRFs to the problem of generating high-resolution range images. A new generation of range sensors combines the capture of low-resolution range images with the acquisition of registered high-resolution camera images. The MRF in this paper exploits the fact that discontinuities in range and coloring tend to co-align. This enables it to generate high-resolution, low-noise range images by integrating regular camera images into the range data. We show that by using such an MRF, we can substantially improve over existing range imaging technology. This paper was presented as a poster at the 19th Annual Conference on Neural Information Processing Systems (NIPS05) in December, 2005, in Vancouver, British Columbia.
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Abstract— We present a Bayesian technique for the reconstruction and subsequent decimation of 3D surface models from noisy sensor data. The method uses steerable probabilistic models of the measurement noise, and combines them with feature-enhancing prior probabilities over 3D surfaces. When applied to surface reconstruction, the method simultaneously smooths noisy regions while enhancing features, such as corners. When applied to surface decimation, it finds models that closely approximate the original mesh when rendered. The method is applied in the context of computer animation, where it finds decimations that minimize the visual error even under non-rigid deformations. This paper was published in the January 2006 edition of ACM Transactions on Graphics (TOG).
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Abstract— We present an algorithm for creating globally consistent three-dimensional maps from depth fields produced by camera-based range measurement systems. Our approach is specifically suited to dealing with the high noise levels and the large number of outliers often produced by such systems. Range data is filtered to reject outliers within each scan. The point-to-plane variant of ICP is used for local alignment, including weightings that favor nearby points and a novel outlier rejection strategy that increases the robustness for this class of data while eliminating the burden of user-specified thresholds. Global consistency is imposed on cycles by optimally distributing the cyclic discrepancy according to the local fit correlation matrices. The algorithm is demonstrated on a dataset collected by an active unstructured light space-time stereo vision system. This paper was presented at the IEEE/RSJ
International Conference on Intelligent Robots and Systems (IROS04) in Sendai, Japan, in
September 2004.
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Summary— This work is in the area of computational fluid dynamics. We present an algorithm for accurately modeling high-energy supersonic plasma flows, such as those encountered in the atmospheric re-entry of a spacecraft. The abstract and paper from the conference are included below. Also included is a highly-detailed technical report from the VKI. This paper was presented by Professor Gérard
Degrez at the Third
International Conference on Computational Fluid Dynamics (ICCFD3) in Toronto in June, 2004, and
subsequently published in
Springer's Lecture Notes in Physics.
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