We present direct multichannel tracking, an algorithm for tracking the pose of a monocular camera (visual odometry) using high-dimensional features in a direct image alignment framework. Instead of using a single grayscale channel and assuming intensity constancy as in existing approaches, we extract multichannel features at each pixel from each image and assume feature constancy among consecutive images. High-dimensional features are more discriminative and robust to noise and image variations than intensities, enabling more accurate camera tracking. We demonstrate our claim using conventional hand-crafted features such as SIFT as well as more recent features extracted from convolutional neural networks (CNNs) such as Siamese and AlexNet networks. We evaluate the performance of our algorithm against the baseline case (single-channel tracking) using several public datasets, where the AlexNet feature provides the best pose estimation results.

This paper introduces GUMS, a complete projection model for omnidirectional stereo vision systems. GUMS is based on the existing generalized unified model (GUM), which we extend in order to satisfy a tight relationship among a pair of omnidirectional views for fixed baseline sensors. We exemplify the proposed model's calibration via a single-camera coaxial omnistereo system in a joint bundle-adjusted fashion. We compare our coupled method against the naive approach where the calibration of intrinsic parameters is first performed individually for each omnidirectional view using existing monocular implementations, to then solve for the extrinsic parameters as an additional step that has no effect on the intrinsic model solutions initially computed. We validate GUMS and its calibration effectiveness using both real and synthetic systems against ground-truth data. Our calibration method proves successful for correcting the unavoidable misalignment present in vertically-configured catadioptric rigs. We also generate 3D point clouds employing the calibrated GUMS systems in order to demonstrate the qualitative outcome of our contribution.

In this paper we present a navigation system for Micro Aerial Vehicles (MAV) based on information provided by a visual odometry algorithm processing data from an RGB-D camera. The visual odometry algorithm uses an uncertainty analysis of the depth information to align newly observed features against a global sparse model of previously detected 3D features. The visual odometry provides updates at roughly 30 Hz that is fused at 1 KHz with the inertial sensor data through a Kalman Filter. The high-rate pose estimation is used as feedback for the controller, enabling autonomous flight. We developed a 4DOF path planner and implemented a real-time 3D SLAM where all the system runs on-board. The experimental results and live video demonstrates the autonomous flight and 3D SLAM capabilities of the quadrotor with our system.

This paper shows and analyzes the execution of a molecular dynamic application that uses Message Passing Interface (MPI) mechanism-Gromacs MPI-over a cloud infrastructure (UnaCloud) supported by desktop computers. The main objective is to find a solution to support Gromacs-MPI on UnaCloud. This coupling was carried out in order to predict and to redefine the Helicobacter pylori Cag A protein 3D structure. Although the structure of eight indigenous sequences was obtained, the handle of resource discovery and failure recovery on the opportunistic infrastructure was achieved manually, restricting the application scope of the solution. To eliminate these restrictions, a mechanism to automate the process execution on UnaCloud was identified and proposed.

An RGB-D camera is a sensor which outputs range and color information about objects. Recent technological advances in this area have introduced affordable RGB-D devices in the robotics community. In this paper, we present a real-time technique for 6-DoF camera pose estimation through the incremental registration of RGB-D images. First, a set of edge features are computed from the depth and color images. An initial motion estimation is calculated through aligning the features. This initial guess is refined by applying the Iterative Closest Point algorithm on the dense point cloud data. A rigorous error analysis assesses several sets of RGB-D ground truth data via an error accumulation metric. We show that the proposed two-stage approach significantly reduces error in the pose estimation, compared to a state-of-the-art ICP registration technique.

We present a novel catadioptric-stereo rig consisting of a coaxially-aligned perspective camera and two spherical mirrors with distinct radii in a “folded” configuration. We recover a nearly-spherical dense depth panorama (360°×153°) by fusing depth from optical flow and stereo. We observe that for motion in a horizontal plane, optical flow and stereo generate nearly complementary distributions of depth resolution. While optical flow provides strong depth cues in the periphery and near the poles of the view-sphere, stereo generates reliable depth in a narrow band about the equator. We exploit this principle by modeling the depth resolution of optical flow and stereo in order to fuse them probabilistically in a spherical panorama. To aid the designer in achieving a desired field-of-view and resolution, we derive a linearized model of the rig in terms of three parameters (radii of the two mirrors plus axial separation from their centers). We analyze the error due to the violation of the Single Viewpoint (SVP) constraint and formulate additional constraints on the design to minimize the error. Performance is evaluated through simulation and with a real prototype by computing dense spherical panoramas in cluttered indoor settings.