9 votes

How do monocular visual odometry algorithms work?

Monocular vision is a difficult and very interesting, particularly in its application to the general navigation problem. I will make an attempt at answering your questions, but if you find anything ...
JSycamore's user avatar
  • 926
8 votes

SLAM: Why use two cameras (stereo) if SLAM can be done using single camera (monocular)?

The most important point is the scale. If you do monocular SLAM, your map will only be accurate up to scale so that you e.g. cannot compute the length of the travelled path in meters. The scale ...
FooTheBar's user avatar
  • 1,375
2 votes
Accepted

How to properly initialize every new pose in a Visual SLAM algorithm (namely DSO)?

DSO initializes the scene and camera poses with a specific scale factor such that the average inverse depth of the pointHessians is one. After the initialization the first two frameHessians are led ...
felipe7's user avatar
  • 36
2 votes

Scale estimation in datasets for monocular odometry

The absolute scale cannot be estimated if you are utilizing a monocular camera. Either you add an additional sensor information such as IMU or you need a size known object to be in your dataset. As ...
Chanoh Park's user avatar
  • 1,567
2 votes

Scale estimation in datasets for monocular odometry

Assume something, then adjust your guess based on your measured distance traversed versus actual distance traversed. If you can get data from a vehicle that drove down a road, and you know the path ...
Chuck's user avatar
  • 16k
2 votes
Accepted

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

From the webpage for the dataset: All sequences contain mostly exploring camera motion, starting and ending at the same position: this allows to evaluate tracking accuracy via the accumulated drift ...
Adam Williams's user avatar
2 votes

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

NaN values are sometimes used to indicate unavailable data. Is it possible that these are simply portions of the dataset for which ground truth was not available, but you can still evaluate on the ...
surtur's user avatar
  • 324
2 votes
Accepted

ROS Publish Stereo Image From 2 USB Cameras

You can write a simple node which subscribes to the 2 RGB feeds, uses blob matching (look up Stereo matching in OpenCV or Stereo Binary SGBM) to create the stereo image, and publishes it. Alternately, ...
jaskaran singh sodhi's user avatar
1 vote

Reconstruct 3d positions of markers relative to each other without camera localization

This is definitely feasible by using visual fiducial markers. Usually you would use a motion capture system (Vicon etc) for that, so if you have one available or can get access to one, that should be ...
Bernd Pfrommer's user avatar
1 vote

Scale factor of Monocular SLAM (Simultaneous Localization and Mapping )

GPS is a good idea. Draw a trajectory using the GPS and align/scale it to your slam trajectory. But if your drone movement is small (few meters) it is not a solution. Or you can just put a scale known ...
Chanoh Park's user avatar
  • 1,567
1 vote

Use 2 Cameras as 1 Stereo Camera

Yes, it is possible. That is often called a heterogeneous stereo camera. Step1: stereo camera calibration. Find relative camera location to each other (extrinsic). Find camera lens distortion ...
Chanoh Park's user avatar
  • 1,567
1 vote
Accepted

Mono VIO vs. Stereo-Camera to recover Depth Information

You are basically describing an object 3D-reconstruction device. Though usually they use a turntable and fixed camera, but the principle is the exact same. See how this dataset were created. I also ...
edwinem's user avatar
  • 1,861
1 vote

Performing Image alignment using pyramid levels with semi dense depth

I'm going to try to answer this question but please don't flame me if I got something wrong. Those were two heavy papers and I didn't have as much time as I wish to go through them. The pyramids are ...
Malcolm's user avatar
  • 571
1 vote
Accepted

Why do strong rotations affect Monocular Vision based Visual Odometry?

The problem of the pure strong rotation is that the image will become easily blurred unless you use 1000FPS camera. This kind of super-strong rotation often occurs in hand-held camera motion. Simply ...
Chanoh Park's user avatar
  • 1,567
1 vote
Accepted

How to perform active search in point feature based monoSLAM?

This is not the answer of your question but ORB is a feature detection algorithm. Feature detection and tracking are different. Once you found a feature it is better to track them by a feature ...
Chanoh Park's user avatar
  • 1,567
1 vote
Accepted

How to tringulate many projections of a point to optimal postion?

I will assume, similar to OpenCV, that each camera is a pinhole camera, so you already corrected for things like lens distortion. In this case each visible point in 3D space $(x,y,z)$ gets projected ...
fibonatic's user avatar
  • 941
1 vote
Accepted

How can I estimate depth of a feature point / object using single camera?

Researchers from Davide Scaramuzza's group authored a paper in 2014 about a probabilistic technique called REMODE that estimates depth from a single moving camera. The algorithm performs per pixel ...
HighVoltage's user avatar
  • 1,096
1 vote
Accepted

Forward monocular stereo vision (Structure from Motion)

It turns out this can easily be done with OpenCV - just find image features (FAST etc.) in first image, track them to the second image (get a set of corresponding features between two images) and then ...
Kozuch's user avatar
  • 643

Only top scored, non community-wiki answers of a minimum length are eligible