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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
9 votes

Camera selection for long range stereo vision system (up to 100 meters)

I still think this is off-topic, but it seems I need more space than a comment to show (answer?) why that is so. You are starting from some performance specifications and are looking to get to a set ...
Chuck's user avatar
  • 16k
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
4 votes

Why are two cameras mounted in paralle in stereo application?

Each camera needs to be defined by 6 variables (3 position, 3 orientation). This would mean that during the calibration process, a solver needs to find 12 variables. As this is done usually with an ...
Arun Lakshmanan's user avatar
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
3 votes

Stereo Camera calibration with different camera types

It looks like what I saw when a colleague of mine was working with fisheye lenses; I found this post after doing an image search for "rectify fisheye image" and following the link from this picture. ...
Chuck's user avatar
  • 16k
3 votes

Estimate Disparity Error for Depth Accuracy Estimation

The answer is that the Disparity error depends on the accuracy of the matching algorithm which matches the points in the two images. Some of these algorithms have an accuracy of one pixel, some ...
Silvan's user avatar
  • 91
3 votes

Camera selection for long range stereo vision system (up to 100 meters)

I'll try to explain this in terms of software. Firstly, it is just next to impossible to have 100 metres (practically, 3 metres is like the best depth accuracy) and we need to be sure that the cameras ...
Prasad Raghavendra's user avatar
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
2 votes
Accepted

Once matching features are computed between a stereo pair, how can they be tracked?

This will depend a bit on how you are detecting your features and how you are estimating motion between frames. Classic approaches would start with detecting SIFT-like features in each image, which ...
surtur's user avatar
  • 324
2 votes

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

This isn't an answer so much as a series of questions to get you to consider an appropriate solution. I will, as usual :-), echo @BendingUnit22 and @Gouda - you appear to be fixated on a particular ...
Chuck's user avatar
  • 16k
2 votes
Accepted

Stereo Vision Using Compute Module: Pi camera synchronization

You need real camera synchronization which means using cameras that both have external trigger capability (it is like the "remote shutter" on consumer/DSLRs). What you do is feed a common trigger ...
Kozuch's user avatar
  • 643
2 votes
Accepted

Cosine interpolation between two transformation matrices?

Yes, you can. same as for the translations, you extract the 3 angles form the matrix, you have the starting angles and the target angles. Interpolate as you wish (sync-async, cos-spline-linear) and ...
50k4's user avatar
  • 6,682
2 votes

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

Like other already answered. Cameras typically are much cheaper than Laser Range Finders. When you talk about camera you mean the 2D cameras isn't it? There are some 3D cameras like the ifm O3D3xx ...
graugans's user avatar
2 votes

Estimate Disparity Error for Depth Accuracy Estimation

Disparity error varies greatly with the algorithm you're using to compute stereo. There are a number of benchmarks for evaluating the quality of different stereo algorithms. See, for instance The ...
surtur's user avatar
  • 324
2 votes

Trigger two usb cameras at the same time

As you say, you can't trigger them at the exact same time without hardware capable of doing so. Some IMU's supply an external trigger pin, and I see no reason why you couldn't buy cameras that have a ...
sdfgeoff's user avatar
  • 151
2 votes

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?

The process you need to go through is actually similar to the camera calibration procedure in OpenCV or other software. The chessboard is replaced by your robot, and you can skip the intrinsic ...
edwinem's user avatar
  • 1,891
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
2 votes
Accepted

Making sense of disparity values after applying `StereoSGBM` from OpenCV

Looking into the documentation of StereoSGBM I found the following explaination link. It says: Some algorithms, like StereoBM or StereoSGBM compute 16-bit fixed ...
vyi's user avatar
  • 215
1 vote

Effect of camera misalignment errors in dual cameras

Because each have diferent reasons (and so can be helped/worsened in different ways). And the calibration will help only in specific setup and needs be done differently for different setups. The ...
gilhad's user avatar
  • 453
1 vote

Is there a better way to deal with untextured regions in stereo matching

I don't know about stereo matching but there are some "direct" monocular odometry/SLAM libraries that do not use common image features but rather whole image edges and gradients and are said to need ...
Kozuch's user avatar
  • 643
1 vote
Accepted

Google's 'Tango' - How it works and what's special about the hardware?

I suspect, but don't know, that the Tango uses a variant of volumetric reconstruction using a Truncated Signed Distance Function (Good intro at http://www.cs.nyu.edu/courses/fall12/CSCI-GA.2945-001/dl/...
Dave Durbin's user avatar
1 vote

Using Standard Digital camera for Computer Vision

First make sure you have the camera's drivers available for the operating system you'll be running your code on. If drivers are available for your platform check what resolutions and fps(s) you can ...
user2967920's user avatar
1 vote

Using Standard Digital camera for Computer Vision

If the university project is not directly about making a drone detection system using visual technic, it may not be worth the effort to connect the "camera" to the computer. (You may have to install ...
Gürkan Çetin's user avatar
1 vote

Why are two cameras mounted in paralle in stereo application?

Making them parallel is beneficial for reducing distortion after a rectification. We usually rectify two images for a fast matching. If speed is not your concern you can skip the rectification stage.
Chanoh Park's user avatar
  • 1,577
1 vote

Stereo camera vs. one camera for player detection & ball tracking in basketball scenes?

100 feet seems too far given the occlusions (like player's hands masking or player's body covering the ball while dribbling). So, I would suggest multiple cameras with linear Kalman tracking (...
Prasad Raghavendra's user avatar
1 vote

Is it possible to detect road surface or navigation area using LRF data or other laser data in a Park?

Is it possible to detect road surface (not grass) using LRF data or other laser sensors? Yes it is possible. A laser scanner will give distance measurements along a scan line. Presumably, the road ...
JSycamore's user avatar
  • 926
1 vote

Stereo camera pair focal lengths

You're just using the focal length as part of a camera model. All you really care about is exactly what the image you posted depicts - that you can correlate a particular pixel with an angle. If ...
Chuck's user avatar
  • 16k
1 vote

Depth accuracy of the stereo camera

You have to "estimate" your disparity error somehow (depending you the stereo matching algorithm used etc.) and you should be set. f and b are camera constants and z is the depth in which you make the ...
Kozuch's user avatar
  • 643

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