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17 votes

Why do people use camera instead of laser sensor for robot navigation?

A 3D laser range finder or LIDAR such as the one on the Google Car is far more expensive than a camera. The other reason is that while in case of a LIDAR the distance of every pixel is available, the ...
Bence Kaulics's user avatar
11 votes
Accepted

AprilTag vs Aruco markers

Aruco (as implemented in OpenCV): Pros Easy to set up (with readily available aruco marker generator, opencv & ros implementation, etc.) fewer false detection (with default parameters) Cons ...
Rufus's user avatar
  • 486
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
8 votes
Accepted

Why do robots need rangefinders while animals don't?

Animals and robots both need to understand something about the 3D structure of the world in order to thrive. Because it's so important, animals have evolved a huge number of strategies to estimate ...
Peter Corke's user avatar
  • 1,702
7 votes

What is the best SE3 library for python?

Writing your own package is always the best way to learn. If you want to try something premade here are a few packages to choose from: Spatial Math Toolbox for Python Python3+numpy+scipy, also ...
Peter Corke's user avatar
  • 1,702
6 votes

How can I improve ZED Camera precision?

I don't know what you mean by "precision" and how do you measure it. The sensing accuracy will probably go back to the camera calibration precision and the stereo matching algorithm used. If they ...
Kozuch's user avatar
  • 643
6 votes

Which is the best visual fiducial marker (2D barcode)?

AprilTag is the state-of-the-art solution for pose estimation. The library itself already has pre-built functions to compute the marker position, given its size. The pose is estimated by homography ...
valleymanbs's user avatar
5 votes
Accepted

Are there any advantages to using a LIDAR for SLAM vs a standard RGB camera?

My question: are there cases where you'd still need a LIDAR or can this expensive sensor be replaced with a standard camera? ... A each one of them has its advantages/disadvantages. Thus in some ...
AL-ROBOT's user avatar
  • 319
5 votes

Why is a computer vision system similar to the human vision

I would argue that the similarities are largely superficial. More "classical" machine vision approaches focused on finding features a human can identify such as lines, texture and blobs of color. ...
combo's user avatar
  • 450
5 votes
Accepted

What is the best SE3 library for python?

ROS's tf.transformations.py has self-contained code for doing these functions and can be used without installing ros. In fact, the python code only depends on numpy! transformations.py
Ari Onasafari's user avatar
4 votes

What the name of this kind of computer vision?

In general, markers used to measure position visually are called fiducial markers. Some applications have a single type of fiducial (a solid circle or a cross) repeated many times. Some applications ...
David Cary's user avatar
  • 4,545
4 votes

Why do people use camera instead of laser sensor for robot navigation?

In addition to those points in Bence's answer, cameras can: Calculate many complex features that result in very robust matching between frames, and object recognition High angular resolution (typical ...
Gouda's user avatar
  • 902
4 votes
Accepted

Smart camera image processing on embedded GPU vs. in the cloud

Performance differences between using an embedded GPU vs. the cloud? For your context (to my mind, gesture recognition would ideally be realtime), the latency of going over the cloud would push me ...
OpenSorceress's user avatar
4 votes
Accepted

Determine the relative camera pose given two RGB camera frames in openCV-python

If you understand how relative pose estimation works in theory, it should be quite trivial to translate it into OpenCV code. First, you can pick any feature detection/description approach you like (...
HighVoltage's user avatar
  • 1,106
4 votes
Accepted

Why do we need a marginalization in Bundle Adjustment?

I am still not entirely sure what you are asking, but I believe this may answer your question. Also note I myself don't fully understand all the details behind the marginalization trick, but I will ...
edwinem's user avatar
  • 1,871
4 votes
Accepted

Robotic Hand Grasp Planning - How do I find the initial contact point for each finger when grasping an object?

This is an excellent question that is currently being explored directly by field experts. Here are some of the latest publications that consider the problem you are encountering: Robotic Grasping of ...
koverman47's user avatar
4 votes

Why do robots need rangefinders while animals don't?

Vision is actually one kind of rangefinder, although passive. Earlier camera use parallax to find the distance and focus. Nowadays, active rangefinders are developed such as ultrasonic sensors, lidar ...
tony.h's user avatar
  • 61
4 votes
Accepted

Visual Odometry terminology: Scale, Relative scale, absolute scale

What does the absolute scale mean? In this context, scale refers to what property related to an image? Essentially scale refers to the size of the object/scene that the camera sees. As a projective ...
edwinem's user avatar
  • 1,871
3 votes

Why do people use camera instead of laser sensor for robot navigation?

navigation in urban environments Depending on the laser, there might be legal constraints on where you can use it. Running around town throwing laser rays around might require special permission/...
Bending Unit 22's user avatar
3 votes
Accepted

Difference between 3D Camera(using IR projection) and Stereo Camera?

"3D camera" is a generalisation that covers sensors that can observe a point-cloud or depth map of the scene they are observing. Some 3D cameras use a projector (via various ways) to improve the ...
Gouda's user avatar
  • 902
3 votes

Is it a bad-design decision to implement high number of moving parts in an automation-robot?

Tough to say without knowing much about the project. More parts = more problems or potential points of failure. A simple design is typically better in that there are less things that can go wrong. If ...
user241585's user avatar
3 votes

Public dataset for monocular visual odometry

http://vision.in.tum.de/data/datasets/rgbd-dataset This is a set of recordings for the Kinect and Asus Xtion pro, which are all indoors (in offices and a hangar). It comes with precise ground truth ...
FelEnd's user avatar
  • 176
3 votes

Public dataset for monocular visual odometry

This is another more recent one, based on the paper A Photometrically Calibrated Benchmark For Monocular Visual Odometry by Engel et al: http://vision.in.tum.de/data/datasets/mono-dataset This gives ...
Stephen Phillips's user avatar
3 votes

Using C++ to control a drone

You could use ROS. There's AR Drone Autonomy for well.. Parrot AR-Drones. TUM ARDrone from the Technical University of Munich, who used that with OpenCV to control a drone. You can simulate a drone ...
Elad Den's user avatar
  • 131
3 votes
Accepted

Kalman filter for vision based pose estimation: 'good' measurements not improving system covariance

First, let me see if I can summarize your issue to see if I understand correctly: 1) Start in area with bad measurements (high R), get P1 2) Move to area with good measurements (low R) 3) Move back to ...
ryan0270's user avatar
  • 2,814
3 votes

What is the best SE3 library for python?

I wrote my own and learned useful things about numpy and python object initialization in the process. I don't regret it.
hauptmech's user avatar
  • 4,445
3 votes

What is the best SE3 library for python?

Klampt Library by Kris Hauser is very good and implement a lot of distances functions including SE3 (R3 + SO3). I use Klampt for some robotic arms applications
hugosc's user avatar
  • 73
3 votes

What is the best SE3 library for python?

I'm surpised nobody mentioned Scipy. Easy to use, mature, great docs, huge community.
Rexcirus's user avatar
  • 248
3 votes

What is the best SE3 library for python?

You should decide whether you would like built-in visualization tools or a coordinate frame management system, or something a little more bare-bones. As stated, ...
Mitchell Allain's user avatar
3 votes
Accepted

Question about Lens distortion

You can only say that the distorted image coordinates are in the range (0-240, 0-180), since that's the image you are starting with. Typically you assume the dimensions of the undistorted image as ...
Peter Corke's user avatar
  • 1,702

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