Questions tagged [stereo-vision]

stereo vision is the extraction of 3D information from digital images, such as obtained by a CCD camera.

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RTABMAP with stereo cameras, mapping along the wrong axis, and odometry is all over the place

I"m trying to setup a robot to do stereo mapping with rtabmap, and depthai's Oak-D-Pro cameras. Mainly testing with gazebo at the moment. When I rotate the robot in gazebo the TF tree rotates ...
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opencv StereoSGBM disparity parameters

In my setting I am using a stereo camera which has a baseline of b = 0.092m and a focal lenght in pixels of fx = 256.667. So that when I want to constrain my setup to detect points up to a maximum ...
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65 views

I am trying to use opencv_cam pkg in ros2 humble with a csi stereo camera imx219-83 in a jetson nano and I get green screen

I am trying to use opencv_cam in ros2 humble for a csi stereo cam in a jetson nano. When I run the node : ros2 run opencv_cam opencv_cam_main ,it publishes the ...
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Estimating extrinsic parameters in stereo vision via sensors

I have multiple (around 6) cameras with a distance of around 4 meters to each other filming an object and I want to reconstruct the 3D shape of it. The cameras are attached to tripods and thus can be ...
1 vote
1 answer
145 views

Calculating the depth in a general stereo vision system

When calculating the depth of a pixel using two cameras, most of the literature I have read describes stereo vision with the cameras having parallel optical axis as shown in the picture below. Because ...
1 vote
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How to compute estimated variance for each disparity value?

I am trying to implement the paper titled Free Space Computation Using Stochastic Occupancy Grids and Dynamic ProgrammingHerńan Badino, Uwe Franke, Rudolf Mester available at this link The overview (...
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How to get an axis in camera coordinate system pybullet?

I am using pybullet to render a robot simulation. This robot have 2 joints and hence, 2 corresponding axes of rotation. I know that when I use getJointInfo on this ...
1 vote
1 answer
164 views

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

I just started with Kitty Stereo Dataset (2015). The first thing I did was compute the disparity using the stereoSGBM class. And here is the rectified input images ...
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64 views

Stereo Bundle Adjustment

When doing stereo based visual odometry and bundle adjustment how does the stereo constraint get factored into the photometric error? Do you use the fact the second cameras location is known wrt the ...
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1 answer
80 views

How does dense mapping/voxel occupancy grid map work with bundle adjustment?

When running for example some version of Orb Slam with stereo vision you're using sparse features for tracking but you can also infer a full depth map. I am curious how you use that full depth map to ...
5 votes
3 answers
7k views

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

I am currently busy with a final year project which requires me to track people walking through a doorway. I initially thought this may be possible using a normal camera and using some motion ...
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1 answer
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Explanation of the epipolar constraint in stereo imaging

I am watching this video, in which the epipolar constraint is defined as $x_l \cdot (x_l \times t)=0$ It means that the vector $x_l$ that passes through the observed point and the left camera origin ...
12 votes
7 answers
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Why do people use camera instead of laser sensor for robot navigation?

I am working on Robot localization and navigation in urban environments. I want to use a camera. But I am a little bit confused about LRF (laser range finder) data or other laser data. Why people want ...
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272 views

Uncontrolled drift of Visual Inertial Odometry

I'm trying to use the VINS-Fusion package to obtain odometry for a quadcopter. The primary sensor is an Intel Realsense D435i. I've calibrated the camera and IMU extrinsics using Kalibr. IMU ...
6 votes
3 answers
8k views

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

I want to implement a real-time stereo vision system for long range (up to 100m) depth estimation. I know that there are some general considerations as described in this SOV post. I have seen some ...
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42 views

How to find fundamental matrix based on other fundamental matrix and camera movement?

I am trying to speed up some multi-camera system that relies on calculation of fundamental matrices between each camera pair. Please notice the following is pseudocode. ...
3 votes
1 answer
104 views

Assistance in finding correct LIDAR for short-range object detection task [closed]

I am working on a task that involves finding a distance of a moving object going a static linear object, e.g a long pole. After trying some approaches (mostly involving stereo vision), I have come up ...
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1 answer
254 views

ROS Publish Stereo Image From 2 USB Cameras

I have two monocular USB cameras and I want to use ROS to make it a stereo camera. I am having a hard time finding a ROS package that consumes 2 monocular camera image streams and publishes a depth ...
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161 views

Cheap global shutter cameras with external synchronization

Please recommend cameras for multi-camera setup satisfying the following conditions: Relatively cheap (up to 100$ per camera). Global shutter. No filters on lenses or pixels. Resolution of 1 MP or ...
1 vote
1 answer
423 views

Use 2 Cameras as 1 Stereo Camera

I have one Picamera and one normal USB Webcam and would like to use them together as one stereo camera. Is this even possible as the 2 cameras aren't exactly the same? I would like to use them in ROS ...
1 vote
0 answers
39 views

Ground based path generation from RGBD camera

How does one generate a trajectory for a ground vehicle using an RGBD camera? For a drone it's simpler since you're not constrained by having to move on the ground but it's not clear to me how ...
1 vote
1 answer
262 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 ...
2 votes
0 answers
52 views

Choosing cameras for stereo vision system?

I'm in the process of building a stereo vision system with YOLO detection. The system have to detect airplanes in far distance and also measure the depth from the airplane to the camera. I think ...
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2 answers
87 views

Trajectory planning in unstructured environments

How is trajectory planning normally carried out in off-road/unstructured environments? In particular I'm interested in how stereo vision can be used to plot trajectories over obstacles - for example, ...
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1 answer
199 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 ...
1 vote
0 answers
95 views

Size of smallest feature from pixel depth resolution

How do I get the size in mm of the smallest feature a depth camera can detect? Known variables are: distance from the target (for instance 1 meter), depth resolution in pixels (for instance 1280 x 720)...
1 vote
1 answer
188 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 ...
0 votes
1 answer
35 views

Number of pixel comparison needed to establish correspondence

I am reading the paper titled Variable Baseline/Resolution Stereo David Gallup, Jan-Michael Frahm, Philippos Mordohai, Marc Pollefeys Section 3 of the paper talks about the time complexity of the ...
1 vote
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34 views

Triangulation in Stereo-Vision?

I need some help in 3D Positioning system I'm trying to set up. At the moment I am using 2 Calibrated cameras, my strategy is to place an AR Marker on the scene, identify the position of the AR Marker ...
24 votes
4 answers
16k views

How to select cameras for a stereo vision system?

I am in the process of building a stereo vision system to be used on a UGV. The system is for a robot that will be used in a competition wherein the robot is teleoperated to find relatively small ...
2 votes
1 answer
34 views

Active Light Stereopsis: 1 Camera + Projector Vs. 2 Camera + Projector

What is the difference between using 1 Camera and a Projector and using 2 Cameras and a Projector for creating structure from motion? Is it that if we use only 1 camera and a projector then we will ...
0 votes
1 answer
85 views

Tracking 3D motion using a stereo camera

Assuming you have a fixed stereo camera, looking at a rigid object, what are the techniques used to track the object? My google searches lead me to optical flow and similar algorithms, but I believe ...
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42 views

Single Camera + Laser Projector Triangulation

I want to combine a laser line projector (projects a laser plane) and a single web camera to determine the X, Y, Z position of the laser point. I am slightly confused as to how to use the fact that we ...
2 votes
0 answers
55 views

Disparity error in active light stereo systems?

Based on this relationship, if we have to estimate the 'disparity error' of a stereo system which uses active light on the scene - can we estimate the disparity error to be very small? According to ...
3 votes
1 answer
409 views

Short range stereo vision

I am designing a stereo vision system for short depth range (15 cm to 35 cm) and I have some problems about baseline, focal length and depth range. My application is to scan an animal tissue (meat, ...
2 votes
2 answers
668 views

How does structured light improve accuracy in stereo vision?

In my understanding, in order to improve accuracy for the estimation of depth with a stereo vision camera, patterns of light are projected into the scene, because the resulting texture makes it easier ...
0 votes
1 answer
272 views

disparity error to x and y accuracy

This question talks about the depth error ($\Delta$Z) as a function of disparity error ($\Delta$D). I want to do the same for X and ...
6 votes
2 answers
8k views

Estimate Disparity Error for Depth Accuracy Estimation

I would like to get a rough estimate of the depth accuracy / uncertainty of a stereo camera system. For this I would like to use the basic formula in the attached image. What is still unclear to me is ...
0 votes
1 answer
69 views

Questions about customized stereo camera

I am designing my robot and I have quite design issues with the available stereo cameras on a market. For the prototype I am using ZED M but it is too expensive and quite large. The question is, do ...
1 vote
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58 views

Stereo-Calibration with Variable focal cameras

Is it possible to perform stereo-calibration with cameras having variable focus? and if so, how is it done basically?
2 votes
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124 views

Stereo Rectification when Extrinsics are known

Suppose I have two cameras $C_1$ and $C_2$ arranged in a stereo configuration. Let us assume that the camera is free of distortion with ideal intrinsics and that the camera extrinsics $R$ and $t$ are ...
1 vote
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Tracking object in realtime using depth image stream from a RGBD camera

I have an Intel RealSense camera which can stream RGB and depth image. Using those information I want to track an object moving on a table top. More specifically, I want to know position $(x,y)$ and ...
3 votes
1 answer
160 views

Setting up a Structured Light Stereo system

I am trying to get started with a stereo experiment and wanted to know the mistakes I might have made during the experiment. The goal is to calculate the depth map of an object using one light ...
6 votes
3 answers
15k views

Hand Eye Calibration

I'm trying to use a dual quaternion Hand Eye Calibration Algorithm Header and Implementation, and I'm getting values that are way off. I'm using a robot arm and an optical tracker, aka camera, plus a ...
3 votes
1 answer
2k views

Trigger two usb cameras at the same time

I'm studyng stereo cameras, and I want to build one. I searched a lot in internet, and the opinions are quite different about this topic. Basically, my question is: Can I synchronize two usb ...
4 votes
2 answers
170 views

Why are two cameras mounted in paralle in stereo application?

For stereo cameras on the market, two cameras are always mounted side by side and with a displacement that is perpendicular to the cameras’ optical axes. I take this setup for granted. One idea came ...
5 votes
2 answers
7k views

How can I improve ZED Camera precision? [closed]

I'm using Stereolabs ZED camera for my computer vision project. I did a small research about several sensors on the market and ultimately we decided to go with the ZED Camera. However I'm finding ...
4 votes
2 answers
6k views

Depth accuracy of the stereo camera

I am doing a project on calibrating stereo ZED camera and finding its accuracy and compare with the Manufacturer's accuracy of 1% at 1m depth accuracy. For this purpose , the formula to calculate the ...
4 votes
4 answers
2k views

Which micro-controler/processor to be used for autonomous stereo vision robot system?

I am very new two robotics, however I have a working stereo algorithm which I want to combine with a SLAM algorithm. I am developing this system for an other application but I decided integrating it ...
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1 answer
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How to set tag arguments of stereo camera plugin (libgazebo_ros_multicamera.so)?

I have some questions about how to use "libgazebo_ros_multicamera.so" plugin. what does tag arguments mean ? Some arguments are both set in and , for example distortion arguments like , ...