# Questions tagged [visual-odometry]

visual odometry is the process of determining the position and orientation of a robot by analyzing the associated camera images.

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### Relative scale problem

I am doing Monocular Visual Odometry, and I have problem with relative scale. Most of the time its value is between 0.8-1.1, but sometimes it goes crazy and it has value 3,4 and once it had value 25. ...
74 views

### Performing Image alignment using pyramid levels with semi dense depth

To gain some confidence, I want to implement the camera tracking (optimization problem) discussed in Semi Dense Visual Odometry for a monocular cameraJ Engel, J Strum, D Cremers E(\xi) = \underset{i}...
50 views

### Pose-Graph Optimization in MATLAB does not give expected results

I am trying to optimize a pose graph I created in MATLAB using either the optimizePoses(viewSet)-function on the imageViewSet that I have or the ...
331 views

### Camera ego-motion estimation via dense optical flow

Help me please resolve some questions in the article 1) "A Robust Method for Computing Vehicle Ego-motion", Gideon P. Stein et al. According to this paper we can find three components of motion (...
48 views

### Which algorithms to locate a static 3D object relative to a moving camera/IMU?

I am using typical setup with camera and IMU as found on a smartphone. Using this, I would like to estimate the relative pose between the camera and an object (for simplicity, let's say a cube). The ...
79 views

### SLAM techniques based on contact, odometry and one front camera

Consider a mobile robot provided with a contact sensor that randomly travels in a closed environment, changing direction every time an obstacle is encountered. Is it possible to reconstruct the 2D map ...
66 views

### Planar Robot Boundary Detection

I am tasked with building a robot that needs to localise and navigate itself on a rectangular surface (like a large desk). The rectangle's shorter sides will be marked with a red tape (or with two ...
40 views

### Accuracy of monocular visual-inertial odometry

I am currently considering to use monocular visual-inertial odometry (VIO) to localize a smartphone relative to a known object. Now, what I would like to understand is, what kind of accuracy I can ...
47 views

### Visual Odometry terminology: Scale, Relative scale, absolute scale

I'm watching a MOOC about Machine Vision for Robotics, but I really do not know the meaning of some vocabulary of this domain. For example, What does the professor mean when he says this: However, we ...
211 views

### Scale estimation in datasets for monocular odometry

Suppose I've developed a monocular SLAM or odometry algorithm. Then I want to test it on some dataset, for example KITTI, TUM etc. How should I deal with the absolute scale in this way? Thanks.
26 views

### Mono VIO vs. Stereo-Camera to recover Depth Information

I have a question. I have found some papers, where they use a Mono-VIO to recover depth of a scene. My question is: Suppose I have a robot arm and attach a mono-VIO system to it. Then I move this arm ...
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### How can we estimate reliable angular motion from a monocular camera?

While I am working on a project, a question comes to my mind; how can we estimate reliable angular motion from a monocular camera, just for a typical indoor environment within a few seconds? So to ...
15 views

### What are the parameters that I need to consider when figuring out the horizontal viewing distance of a camera mounted overhead for effective tracking?

I am currently working on developing a hybrid Indoor Positioning system where images from an overhead camera will be used to identify and track people. I am new to the field of visual tracking and a ...
27 views

### Setting An Initial Pose Rotation In ORB SLAM2

I am running ORB SLAM 2 on a drone with a downward facing, RGBD camera. I'm using Gazebo to simulate and Rviz to see the vision_pose ROS topic (the orientation/...
115 views

### How to find visual odometry by video from cellphone camera mounted on robot?

I am writing codes in python for visual odometry from single camera. I used cell phone camera for testing. I took video of 35 sec with camera moving. I used code below to read first image ...
101 views

### How can I calibrate 3 cameras without knowing global pose of the object & camera locations? How can I find the pose of each camera wrt the first one?

I have camera feed (in the form of RGB images) from 3 cameras with partially overlapping Field-of-view i.e. for the time stamp 0 to 100, I have total 300 frames or say synchronized 100 RGB frames for ...
79 views

### How is the depth estimation done in DTAM / LSD-SLAM (direct VSLAM)?

I know that DTAM and LSD-SLAM both employ the photometric error between two keyframes to estimate the image depth. But I don't know what the photometric error describes precisely. In the DTAM paper, I ...
14 views

### Should I wrap the intrinsic and extrinsic parameters to a single vector during optimization?

I've read the libmv library dedicated to solving the bundle adjustment problem. The author states it's better to wrap the rotation and translation parameters into a single vector during optimization ...
409 views

### What does the normalized image coordinates imply?

In VSLAM or visual odometry, we use a camera matrix P to transform 3D scene points to 2D image points. When using homogeneous representation, we may choose the image coordinates as the normalized ...
114 views

### Custom implementation of robot_localization package

I plan to implement a sensor fusion of IMU + Visual odometry using an EKF. I came across the excellent robot_localization package which does pretty much all that I want. However, I need to use perform ...
40 views

### How does inverse compositional Lucas–Kanade algorithm work?

I am trying to understand the Lucas–Kanade algorithm since I am reading a paper in which is applied the inverse compositional Lucas–Kanade algorithm, but in order to understand the latter I have to ...
45 views

### Problem understanding a paper about visual odometry

I am reading the following paper: SVO: Semi-Direct Visual Odometry for Monocular and Multi-Camera Systems , and I am having some problem understanding some concepts. Before starting I have to say ...
115 views

### What is the definition of the phrase “ego robot”?

What does the phrase "ego robot" mean? I see it used in the context of multi robot systems like in the paper Game Theoretic Motion Planning for Multi-robot Racing by Zijian Wang, Riccardo Spica & ...
152 views

### Is pose estimation using images necessary in visual-inertial SLAM

In visual SLAM, pose estimation is performed between two adjacent frames or keyframes using feature detection and pose estitmation from corresponding features. However in visual-inertial SLAM, pose ...
35 views

### How to derive the camera trajectory from ICP

This may be a very simple question so please bear with me... Suppose I have a stationary object and point clouds, $n$ $(x,y,z)$ points, of that object taken by a moving camera at time steps $t_i$, \$...
126 views

### How to plot the 3D camera trajectory from a VSLAM output

I am totally new to VSLAM algorithms and would want to plot the path followed by the moving camera. I am using the open source implementation of ORB_SLAM2 for a rgb-d camera on benchmark dataset. The ...
195 views

### Why do strong rotations affect Monocular Vision based Visual Odometry?

In context of the paper Semi Dense Visual Odometry for a Monocular Camera J Engel, J Sturms, D Cremers At page 7, last paragraph the author writes The achieved tracking accuracy for two feasible ...
175 views

### How to publish odometry from 3 wheeled omnidirectional robot?

I'm new to ROS and robotics and I'm trying to implement the ROS navigation stack in a 3 wheeled omnidirectional robot. I already made the map using RTABMap but now I'm stuck in the 'Publishing ...
269 views

### In practical terms, how close is the accuracy of camera-based visual odometry/SLAM methods to lidar-based methods for autonomous car navigation?

Benedict Evans, a general partner at Andreessen Horowitz, claims that “almost all autonomy” projects are using lidar for SLAM, and that not all of them use HD maps. An MIT group is testing self-...
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### Map initialization problem in Mono SLAM

I'm reading and trying to implement the paper Monofusion(V. Pradeep, C. Rhemann, S. Izadi, C. Zach, M. Bleyer and S. Bathiche, "MonoFusion: Real-time 3D reconstruction of small scenes with a single ...
107 views

### SE3 composition operator gives unexpected results

Given Data and Algorithm I have a stream of SE3 poses supplied by a basic wheel encoder odometry through ROS message passing system. Odometry publishes data in traditional to ROS ENU coordinate frame ...
171 views

### TU Munich Monocular Visual Odometry Dataset has NaN values in the ground truth data.

I am trying to use the motion sequences in the dataset to create trajectories for VR systems. A major portion of the ground truth data in almost all sequences has NaN values. Is there any other source ...
114 views

### Camera calibration sequence with ground truth data

I'm looking for a SLAM dataset (monocular or stereo) specifically with a checkerboard, meaning the camera always has a checkerboard in frame. Most popular datasets provide calibration sequences, ...
73 views

### Effectiveness of visual odometry algorithms (CPU usage)

My robot needs to obtain visual odometry, with a condition that the used algorithm has to have as low computational requirements as possible and the used camera/sensor shouldn't be very expensive. The ...
171 views

### EKF based SLAM, marginalization and key-frames

I have a couple of tightly related questions regarding EKF-based visual SLAM. It is common in the Kalman based VSLAM litterature to marginalize 3d points and past poses. Condsidering the EKF as a ...
6k views

### How do monocular visual odometry algorithms work? [closed]

What is the core principle of a monocular visual odometry algorithm? I mean, after calibrating a single camera (undistortion etc.) images are fed into an algorithm - what exactly does this algorithm ...
86 views

### Consitent Scale in Monocular pose estimation

I just wanted to know if scale is conserved across multiple images, when doing a process such as monocular odometry. I know in reality the scale tends to drift over time due to accumulation of small ...
1k views

### Scale problem with monocular visual odometry

Is monocular visual odometry able to estimate relative scale? Say I have a sequence of 10 images that are taken on a single track each 1 m after the previous. Can some mono odometry method distinguish ...
375 views

### Pose-graph-slam:using only a camera

I'd like to know how to form my pose graph if the only information I have available is that from a camera, (1) What are my poses? Are they just the accumulated transformations from pairwise matching? ...