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 ...
- 926
6
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 ...
- 1,355
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 ...
- 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 ...
- 1,527
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 ...
- 15.9k
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 ...
- 245
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 ...
- 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, ...
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 ...
- 1,527
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 ...
- 1,527
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 ...
- 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 ...
- 1,527
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 ...
- 1,527
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 ...
- 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 ...
- 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 ...
- 633
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